Darren Burgess was an Australian fitness and conditioning specialist whose appointment at Liverpool in 2010, during a period of unprecedented upheaval across all levels of the club, was attached to that of their head of sports medicine and science Peter Brukner.

Roy Hodgson was drowning as manager and, two weeks before Fenway Sports Group’s takeover, striker Fernando Torres was left out of a Europa League game because of concerns from the new staff about his physical state.

Advertisement

As Torres simmered, Hodgson explained the reasoning behind his absence publicly. This led to claims he had lost control over team selection. Hodgson would last only a few more months at Anfield, but Brukner and Burgess made it to 2012 before they moved on.

Having since represented Arsenal, Burgess now works as a “high-performance manager” back in his homeland. He also does consultancy work for FIFPro, the global union for footballers, which has designed a platform that monitors players’ workload.

Last year, Burgess contributed to a report that outlined the effects of multiple match exposures, including sleep disruption, training consistency, travel fatigue, increased injury risk and mental health issues.

Liverpool players were examined in the study.

Given the findings, perhaps it should not be a surprise that Andrew Robertson has become the latest Liverpool player to be out injured after picking up a knee problem towards the end of the humbling Champions League defeat away to Napoli last week.

Robertson has played more than any other Liverpool player since 2018, having featured in 17,213 minutes of football.

On FIFPro’s tool — which gathered information from 2018-19 to 2021-22 season — the Scottish left-back’s data stands out, especially because of his limited rest and recovery.

Among 270 male footballers, Robertson averaged 122.7 hours break between appearances, the eighth-lowest in a sample that also assessed the number of “critical zone” matches — a reference to the number of times a player featured across consecutive fixtures without at least five days (or 120 hours) of rest separating them.

The study found that 65.1 per cent of Robertson’s games over the past four years have been in the “critical zone”, with 19.5 per cent of games after less than three days’ respite.

Advertisement

Mohamed Salah and Alisson, the goalkeeper, narrowly trailed Robertson in this field of data, which also logs the distance the player has travelled. Egypt captain Salah has flown the equivalent of going around the world 5.6 times for club and country during this period. Brazil international Alisson has done it 7.5 times.

Trent Alexander-Arnold is not included in the research but given that the right-back offers a similar function and isn’t far behind Robertson in terms of overall minutes on the pitch in recent years, you can probably draw similar conclusions about his degree of rest and recovery.

During Torres’ last months at Anfield in the first half of that 2010-11 season, it often seemed like an alien species had taken control of his mind and body. He was just 26 but leading the forward lines at Atletico Madrid and then Liverpool since his teens had taken a toll.

In that 4-1 loss in Naples, along with other games so far in this new season, the performances of some Liverpool players have been reminiscent of the Spaniard’s a decade earlier. Increasingly, Liverpool have been outrun in terms of distance covered as well as sprints — the sort of data Jurgen Klopp takes seriously because he knows where it can lead.

“I love it when I read after the game that we ran more than the opponent,” he said in 2013 after his Borussia Dortmund side won at the Emirates Stadium when his players ran a total of 117km compared to Arsenal’s 106km. “I don’t like winning with 80 per cent possession.”

After similar exertions, his Mainz and Dortmund teams famously crashed in year seven. At Liverpool, he is approaching that same milestone, having always managed to ensure the last game of each season has mattered in some significant way.

In each of his seven completed seasons in charge, including 2015-16 where he succeeded Brendan Rodgers in the October, Liverpool have gone the distance and there is now a public debate about whether some of his players have reached burnout all at the same time.

Advertisement

Though in some individual instances that theory might be proven to be true in the fullness of time, the squad’s preparation for the current campaign is also considered to be relevant — just as it was in the summers of 2020 and 2021, albeit for different reasons.

In 2020, pandemic restrictions played havoc with Klopp’s summer but a year later, he was able to drill the team for nearly a month in the foothills of Austria and France. Klopp has a very basic theory about pre-season: if the players meet his expectations during those weeks, everything that follows becomes a lot easier for them.

That means running lap after lap around an athletics track in searing heat. In completing this process, the players will hit 70km a week, including the friendly matches. When competitive fixtures begin, the anticipated mileage in a two-game week drops to around 55km, which is less than they have been conditioned for but, according to estimations by data scientists at Liverpool, more than at other Premier League clubs.

At Liverpool, there are internal debates about the physiological and psychological benefits attached to these boot camps. Yet as the 2020-21 season proved, and this one seems to be proving, Liverpool’s performances suffer when preparation isn’t well ordered, or when track or pitch time is limited because of far-flung tours that involve the club’s considerable commercial obligations.

By the end of August, five games into the season, Klopp was dealing with injuries to 10 senior players. Those who understand the way he runs his squad best tend to agree that he encounters serious problems whenever two or three players are out at the same time.

This presents the threat of a domino effect.

If a backup player has been completing 28-30km just through training, what happens when suddenly they are expected to do north of 40km a week or as much as 55km, depending on the number of games he is expected to play? The new expectation involves a huge increase in capacity — as much as 25 per cent.

Advertisement

The risks are obvious.

Understanding how Klopp and Liverpool have managed the fitness department across his almost seven years at Anfield merits a closer look.

Klopp has won nearly every trophy he has competed for during his time at Liverpool en route to becoming the longest-serving manager in the Premier League.

One of the principal foundations of the club’s success throughout this period has been Klopp’s connection with his players. Only Jordan Henderson, James Milner, Roberto Firmino and Joe Gomez remain of the group he inherited from Rodgers, but for the past five years, the squad has been relatively settled.

At other clubs, it does not take much for players or their representatives to grumble about a manager, but even in the toughest periods at Liverpool (such as when the reigning champions lost six home games in a row amid a defensive injury crisis over two months in early 2021), there has been loyalty to Klopp. He is one of only a few coaches in world football to command such faith.

Klopp’s trick is to make players feel like he is their friend but not their best friend. Players respect him but they also fear him. They don’t want to let him down. They know their priorities are also his priorities.

The players come first at Liverpool under Klopp. This culture has helped yield outstanding results, incredible seasons and moments that will be remembered for as long as the club exists, but the pursuit of glory had involved a substantial amount of collateral damage.

Klopp operates closely with a coterie of assistants and coaches chosen by him and beyond that, there is a perimeter of support — appointments made by the sporting director. Formerly, that responsibility fell with Michael Edwards and now it is with his successor Julian Ward.

In April, Klopp signed a new contract committing himself to Liverpool until 2026. Key to this extended stay is the allegiance of his inner circle. He would name-check Peter Krawietz and Pep Lijnders, suggesting that he only agreed to remain once he knew they were on board too.

Klopp wasn’t grandstanding when he suggested that had either of those two wanted to move on, he would have seriously considered his own future. This is because he knows Krawietz helps counter-balance some of his sharpest instincts and Lijnders brings the sort of energy he can’t deliver to every training session. Though Klopp did not seek a pay-rise for himself in negotiations with Fenway Sports Group (FSG), he ensured each of his closest lieutenants got one.

Advertisement

It is slightly different if you are placed outside of Klopp’s circle of absolute trust. As with many big clubs and their managers, those on the inside get to see the best and very worst of his moods while those on the outer part tend to get less of the worst but less of the good as well.

Most of the time, a professional distance exists. To many in this position at Liverpool, employment is more of a job. They are paid less and tend to feel more vulnerable about their futures.

Across all levels, staff appreciate that the players are the club’s most valuable pieces of kit. So long as they are happy, then Klopp is usually happy as well. When Edwards was in charge, the same went for the sporting director.

Between 2018 and 2020, Philipp Jacobsen, as head of performance, operated between those central figures and the players. In June, he spoke to the Inform Performance podcast about his general experiences of working in elite football.

“In a way, you are facing a similar amount of pressure to the players,” said Jacobsen, who has also worked at Portsmouth and Greek club Panathinaikos. “The performance of the team directly filters down to the backroom staff. You feel the pressure because they (the players) are pushing you. They (when injured) want to come back early, which is totally normal. You have to try and stay focused on making the right decisions in this high-pressure environment.”

He continued: “The same goes for working with the coaching staff. The areas of interest are different but the same. We all want to win. The difference is they think of the next game and they want to have as many players available as possible. So you have that pressure to deal with as well.

“It’s never an easy conversation to have, with a coaching staff about a player who is not ready. ‘Can he play 30 minutes?’. The reality is you can’t say, ‘Yes, he can’. He might drop out after the first two minutes, he might never drop out. It’s very, very difficult to play that part and it’s the biggest challenge in medical and performance in general.”

Advertisement

For a while at Liverpool, decisions were shared between the players and the physios but that changed when it was suggested to Klopp that he needed to be more involved. With that, discussions became triangular although the responsibility of diagnosis and prognosis remains with the club’s medical staff.

Klopp can be very forceful with his players and he is an effective negotiator but ultimately, if he senses a player really wants to take a certain path to recover from a long-term injury, he’ll trust them. Especially if the medical team aren’t in agreement on how to deal with the situation.

It would hardly be surprising if some staff have agonised about how to express themselves in front of the players, the manager or any sporting director.

Klopp reacts to injuries differently from his predecessor. Whereas Rodgers leaned on positives, stressing that any sort of unavailability provided opportunities to others, Klopp can be emotional.

The reaction is understandable given the pressure of his role and how damaging injuries can be to his plans. But it means the person with the responsibility of telling him about such developments must feel they have been placed in a tough position: if the injury is a bad one and you over-promise, he is unlikely to forget it. If it’s a bad one and you say it like it is, just as training is about to begin, it is likely to draw a reaction.

Klopp is able to be sensitive with players but extended staff see less of that. Any sort of confrontation is later met with a carry-on-regardless attitude. At the next point of contact, he can roar with laughter, slap someone on the back, and continue with his day.

On May 16, German physio Chris Rohrbeck made a surprise, temporary return to the club before the Champions League final. This happened because of concerns about several players’ fitness. At the top of that list was Salah, and he likes Rohrbeck, who had left in 2020 to work at Mainz back home, a lot.

Advertisement

Two days earlier, the Egyptian forward had injured himself in the FA Cup final win over Chelsea. The meeting with Real Madrid in Paris was two weeks away.

Within 48 hours, Rohrbeck was on Merseyside, helping with his recovery. Officials at the club understood that Salah wanted a new contract. Rohrbeck’s return showed him Liverpool were willing to make special allowances in his case.

It was not the first time players have influenced staffing levels.

Lee Nobes, the current head of physiotherapy, was appointed to the role following an extensive recruitment process that involved other serious candidates. While his experience of working within a schedule that involves Champions League football was important, Nobes also understood what it was like to operate at a club who were changing training grounds from his time with Manchester City.

Liverpool’s switch from Melwood to Kirkby was a few years away and Nobes also came recommended from several sources within the industry — notably Milner, who knew him from their five years together at City.

Milner had since emerged as a highly influential member of the squad. He is close to other senior British players in Robertson and Henderson. Jacobsen, then holding a decision-making position at the club, understood the importance of the dynamic and he sanctioned the hiring of Nobes, a character who is said to be similar to Milner: an alpha male with a direct way of communicating.

Klopp loves Milner because of his commitment. Even when he has not been involved in a matchday squad, he has travelled to away games with his team-mates and had an input in the changing room. Milner will call out fellow players for using their phones in parts of the training ground where they are prohibited. Others in the leadership group will let this slide, but never Milner.

When out injured, the former England international will ask the staff lots of questions. While some accept it is up to them to meet his expectations and standards, others have found him difficult to please. Those who have worked with him tend to agree, however, that his absolute devotion to training helps define the culture that Klopp wants.

Advertisement

Milner’s “total” attitude has helped create a supremely competitive environment in the squad. Yet this culture has also had consequences due to conflicting messaging around the benefits of training or rest.

Jacobsen referred to these sorts of pressures across football when he spoke on the Inform Performance podcast: “It might be that a player says, ‘Hey, I feel great — I can go back on the pitch…’. But you know the tissue is not ready, he has not healed yet. He hasn’t done enough work on the pitch. Then, you need to be the sounding board. That’s quite challenging.”

Jacobsen would leave Liverpool, amid a raft of staff departures, just a few months after Klopp guided the team to the club’s first league title in 30 seasons in the summer of 2020.

Two years earlier, he had been appointed by Edwards, having spent a decade at a clinic in Qatar that included working with that country’s national football team. Their association went back to 2005, when they were colleagues at Portsmouth.

It was Jacobsen’s responsibility to bring the medically related departments in line with one another. Despite the huge on-pitch improvements inspired by Klopp, there were long-standing issues behind the scenes between physiotherapists and sports scientists.

During Klopp’s time at the club, there has been friction in this area because of culture clashes. He has never embraced an English-style backroom model but hasn’t imposed a full version of the German system he is more familiar with either.

In the Bundesliga, the bulk of any physio’s work is usually done in a medical studio and they rarely set foot on the training pitch, where the role of the fitness coach kicks in. In England, responsibilities are often broader, with physios following a player’s progress once they return to the grass rather than handing the duties over to the fitness coaches or sports scientists.

Advertisement

Klopp’s decision to appoint countryman Andreas Kornmayer as head of fitness and conditioning during his first pre-season in 2016 exacerbated inter-departmental strains, which were made more complex because of a split between English and Spanish speaking physios, who had different ways of doing things.

Ryland Morgans, the previous fitness coach, had, like his old boss Rodgers, been protocol driven. Morgans left the club late in Klopp’s 2015-16 debut season, a campaign which was marked by a number of hamstring injuries as players struggled to adjust to new and extreme physical testing.

Klopp decided he needed a sergeant major-type to run his fitness department.

When Kornmayer arrived from Bayern Munich, he made headlines because of his appearance. With his distinctive thick-rimmed glasses and swept-back blond-ish hair, he looks a lot like a smaller version of Klopp.

When Xherdan Shaqiri signed from Stoke City in the summer of 2018 having been at Bayern from 2012-15, he was surprised to find Kornmayer holding such an important position at his new club. Kornmayer had not been a senior figure at the German giants but by the time Shaqiri came to Anfield, he was one of the most empowered members of staff, having gained the absolute trust of Klopp.

When Liverpool staff clashed with Newcastle’s during a tempestuous Premier League game last month, Kornmayer was there, at the centre of a touchline face-off which has resulted in fines and bans on both sides.

At the beginning of his time at Liverpool, Klopp had wanted his players to be able to run long distances and Kornmayer was prepared to push them to their limits. This led to friction with sectors within the club that were more process driven. With Kornmayer at the seat of power, the gap between sports scientists’ thinking and the physios’ widened.

Advertisement

With Klopp’s support, indeed, Kornmayer seemed untouchable but his approach did not bring cooperation between each of the medically related departments.

Some staff feared a lack of accountability in the system could potentially impact player availability further down the line and at that point threaten results on the pitch. This environment is thought to have contributed to more than one person’s decision to move on.

Edwards recognised the problem and hired Jacobsen in 2018 to try to bring harmony across the setup.

Jacobsen is said to have challenged Kornmayer on his first day at Melwood. It was immediately clear to lots of staff that it was not going to work out for Jacobsen because of a clash of philosophies — where he wanted to know about the science behind every decision, Kornmayer was more instinctive.

Though Klopp had initially given the impression he was never fully on board with the role and responsibilities of Jacobsen, some senior staff believed it was fundamentally a good idea. It should have fallen to Jacobsen to implement a single but flexible way of working, but this never happened. Instead, beyond Klopp’s inner circle, a common identity was lacking because departments acted according to what they knew and thought.

Liverpool would win the Champions League and Premier League during Jacobsen’s time at the club but by the end of 2020, he had left, returning to Germany on gardening leave.

Sympathisers believe Jacobsen wasn’t able to do what needed to be done because some staff were so wedded to certain roles and responsibilities. Yet it is also thought he didn’t have the status or temperament to bring about what was necessary. He never got to grips with the reality that it was his job to manage personalities as well as injuries.

Still, Edwards rated Jacobsen highly. His contract was paid up in full and he has since acted as a consultant for the Boston Red Sox, the major league baseball team also owned by FSG.

Advertisement

Following Jacobsen’s exit, the system at Liverpool temporarily became more disjointed than before, with each department head trying to convince one another of their ideas without anyone really mediating or leading them. The turnover of staff in the Klopp era has been significant but one consistent presence has been Kornmayer. Despite criticism, there is an acknowledgement that he has ultimately managed to get a huge amount of distance into the players’ legs.

There was a feeling in the medical department after winning the Champions League final in June 2019 that Liverpool needed to start replacing some of the players after two seasons of so many games (56 in 2017-18 as they lost the Champions League final to Real Madrid in Kyiv, and then 53).

To meet Klopp’s expectations for just one season of 50-60km running a week was considered an achievement internally.

The need for change might have been real but when Klopp led Liverpool into another Champions League final in May, his team against Real Madrid included eight of the starting XI that had beaten Tottenham Hotspur in Madrid three years earlier.

A few of Kornmayer’s critics concede that he must have been doing something right.

Ultimately, he has been able to change at least a few people’s opinions of what footballers were capable of achieving with their bodies, pushing them further than some with even the closest inside knowledge thought was possible.

Jacobsen’s exit came just after head of medical services Andy Massey joined FIFA in the spring of 2020.

Massey had told the club in advance of his departure and this allowed Edwards to prepare a replacement. He thought he had convinced Gary O’Driscoll to leave Arsenal before their new head coach Mikel Arteta begged him to stay. Under pressure from his family to remain in London, O’Driscoll pulled out of the move 24 hours before it was due to be announced.

Advertisement

This left Liverpool without a doctor just as the scale of the COVID-19 pandemic was becoming clear and the UK headed into that first period of lockdown. Among internal candidates, Jim Moxon was the surprise choice. His previous experience at Liverpool only extended to the academy but occasionally he would step up to Melwood when other figures were unavailable.

It is believed in some quarters that Nobes favoured Moxon, because his appointment would have allowed the physios to take back some authority in discussions with other departments. Edwards did not have as many options as he might normally because staff from other clubs were reluctant to relocate as Britain jumped from lockdown to lockdown.

Moxon handled the pandemic well, with players and other staff largely falling in line with the safety protocols.

During this period, nobody at Liverpool got seriously ill, though one game, a Carabao Cup semi-final first leg against Arsenal in January this year, was controversially postponed because of a batch of faulty results from tests that, according to rules, did not need to be taken.

Gradually, however, Moxon’s role became more about football and from there, he was judged on his ability to manage staff and arrive at good decisions quickly. He would last less than two years in the role, his departure announced, unusually, on the eve of this season, having been active just a few weeks earlier on the club’s pre-season tour to Thailand and Singapore.

It is said Moxon was more of a temperate character than Klopp and the doctor no doubt did not enjoy battling with the manager’s moods.

As Liverpool seek Moxon’s replacement, Andreas Schlumberger — Jacobsen’s successor as head of performance — has taken on more senior responsibilities. Schlumberger’s association with countryman Klopp goes all the way back to their time as students. Having worked together at Dortmund, Klopp would have liked to bring him to Merseyside sooner than he did.

Advertisement

Since arriving towards the end of 2020, some of Schlumberger’s work has focused on helping the players who are no longer classed as injured but are not ready yet for full training.

Klopp and Mike Gordon, the FSG president, were keen to give him a broader scope so he could try to bring better coordination and communication between the departments led by Nobes, Kornmayer and whoever the club’s next leading doctor turns out to be. Earlier this summer, Schlumberger added Frigyes Vanden Auweele to the staff as the new head of osteopathy.

Schlumberger’s background is in sports science rather than medicine but he has impressed colleagues at Liverpool with his capacity to listen. He is not ego-driven. It is hoped that he will create some balance in the structure beneath Klopp, but Schlumberger’s name currently sits below Kornmayer’s on the club website.

Last season, Schlumberger’s value was marked by Klopp in his programme notes ahead of Leicester City’s visit in February.

Following the previous home game, the FA Cup third-round victory over Cardiff City, Harvey Elliott had thanked club physio Joe Lewis for his help in recovering from an early-season dislocated ankle. While it is true that Lewis did most of the grafting with Elliott on the comeback trail, it is also true that Schlumberger, quietly, had mapped out the rehabilitation programme.

It was not an opportunity Klopp could afford to ignore, given Schlumberger was his own expensive appointment.

Last season, Klopp nearly led Liverpool to an unprecedented quadruple. Having won both domestic cups, they missed out on another championship in the last 15 minutes of the final Premier League matchday as Manchester City rallied from 2-0 down to beat Aston Villa, before losing 1-0 to Real Madrid in the Champions League final.

For only the second time in the club’s history, the team played in every fixture possible. In this pursuit, Kornmayer squeezed every last drop of energy out of the players.

Advertisement

It was understandable that, towards the end of such a gruelling campaign, they collectively struggled to deliver the sort of intensity in performances normally associated with a Klopp team. For the final month, at least, it seemed as though Liverpool got by on magic oils and experience.

The players who have not left, coming off the back of an exhausting sequence of challenges, are now, of course, one year older and that means preparation takes on even greater importance.

Following a very different pre-season schedule compared to 2021, with a shortened European training camp, Klopp reached the end of August with his squad already decimated by soft tissue injuries, which have been the single biggest contributor to absenteeism at Liverpool since 2018-19.

A survey for UEFA, European football’s governing body, suggests soft tissue injuries have increased across the game by 15 per cent over the last decade and that number is only going to go up if schedules continue to be fattened and player treatment doesn’t adjust.

Their efforts over a long period of time, combined with the tactical and physical expectations of the manager, mean Liverpool’s players, with their increasing age profile, are almost certainly more susceptible to injury than they ever before.

A rebuilding programme has already begun and central to considerations in player recruitment from 2018 onwards has been availability.

Initially, Klopp had looked first for explosiveness in any potential signing. Upon becoming Liverpool’s manager, he was astounded by Daniel Sturridge’s capacity to burst away from an opponent. He would soon realise, however, that Sturridge was unable to play in more than 50 per cent of the games. It was the same for the striker at previous clubs Manchester City and Chelsea, and they didn’t ask him to run 55km a week.

Advertisement

The medical department contributed towards a new buy-in that prioritised availability, and presentations were made to FSG. One of the first signings of the new era was Naby Keita, who was available for 78.7 per cent of RB Leipzig’s league games in the season before Liverpool agreed a deal to sign him.

However, Keita’s best season at Anfield was his first in 2018-19, when he racked up 1,390 minutes in the Premier League (40.6 per cent of Liverpool’s total) — a season when his average time on the pitch was also the highest of his Liverpool career at 56 minutes a game. By the end of last season, he had missed 361 days through injury since signing for the club. Given such a track record, it would be understandable if Klopp is reluctant to push him too far when he is in the squad.

An Israeli study has estimated that, on average, Premier League clubs lose £45million due to injury-related reductions in performance each season and this means clubs have a stronger economic incentive than ever to invest in injury prevention and rehabilitation programmes.

Between 2012 and 2017, the study discovered a relationship between the number of days lost due to injury during a season and the difference between a club’s expected and actual finishing positions.: while players spending 136 days out injured caused a team to lose just one league point, missing 271 days cost the team a place in the final league table.

In each of the last three seasons, that theory can be applied to the summit of the Premier League standings.

While Manchester City suffered more than 500 more days lost when Liverpool romped to the title in 2020, the opposite pattern helped swing everything in City’s favour the following season.

This May, City would again finish just ahead of Liverpool, pipping them to the championship by just a point. Compared to Liverpool, Pep Guardiola’s players had spent 303 days less on the treatment table over the season.

Advertisement

The margins could not have been narrower.

(Additional reporting by Mark Carey)

(Top photos: Getty Images; design: Eamonn Dalton)