Neymar always gets checked physically on the field whether with Brazil or Barcelona, but an unintentional knee to the back in the waning minutes of Brazil's 2-1 quarterfinal win against Colombia has reportedly taken him off the field for the rest of the 2014 FIFA World Cup.

The Brazilian star was taken to the hospital by ambulance in order to have images taken of his back and to get the pain controlled, which likely took stronger drugs than could be administered at the stadium.

After the match, Brazilian coach Luiz Felipe Scolari said that Neymar was out for the semifinal match against Germany, per Duncan Castles of SI.com:

While initial reports focused on a fractured rib and Scolari held out some hope for a return, the BBC reported that it was far more serious.

Multiple reports suggest that Neymar has suffered a fracture somewhere in his third lumbar vertebra (L3.) This is one of the vertebrae that is under the most stress due to the shape of the spine.

It is at the heart of the curve in the lower back, which can create force on both the bone itself and on the discs above and below that keep it cushioned. Neymar could be seen grabbing directly at this area while he was laying on the turf.

Most athletic fractures, especially traumatic fractures like the one Neymar suffered, do not have the force to displace the bone significantly. While still dangerous, the spinal cord is seldom at risk as it is in automobile or other high-impact collision injuries. Neymar could be seen to be moving both legs while down and assisting in his transfer to the stretcher, which is a very good sign.

In fact, most fractures will be to the transverse or spinous processes rather than the body of the vertebrae. This is by design, as those processes are there in large part as protection.

However, the other function of the transverse process is to serve as the attachment for the psoas muscle. The psoas attaches to the spine on these processes in the lower back, allowing for hip flexion and extension. This is obviously very important for a quick player like Neymar. 

The L3 level is where some very significant nerves go out into the body. Nerves that control the thighs, lower back and genitals come out at this level. A fracture could cause problems for these nerves if they are impinged in any way. Doctors will have to be careful to make sure that the injury hasn't created any inflammation that could cause further problems, though this is easily controlled. 

Assuming that Neymar does not have any neural deficits, it is unlikely he will need surgery. The normal conservative treatment for this type of fracture is rest. Internal fixation (plates and screws) can be necessary in severe cases, but creating the right curvature of the spine is very difficult. However, it can be very difficult to give a solid timeline for his recovery.

Simply, Barcelona will have to watch and wait. Some doctors like to use a brace of some sort, if only to protect the spine from any jostling or contact, but this is very individual. Normal recoveries can go anywhere from six weeks to as many as six months, though the standard for a non-surgical case is between eight and 12 weeks. 

Once the fracture heals, it will take some time to return to function. The rest will need to be enforced pretty strictly, making it very difficult to stay near to game fitness. It will not only take time to build that, but Neymar will need to be watched closely to make sure that there is no loss of function. There is almost no way to tell that now or during the rehab process.

This is not the way that Neymar wanted to leave the World Cup, on a stretcher, with his team just two games from a title. His skills got the team this far, but facing a tough German squad, perhaps his teammates can carry him to the title and see if he's healthy enough to raise the Cup with them in a week.