Instead, NFL teams use futures contracts to claim the rights to players they think will be able to make some noise in the upcoming season.

Just after the 2013 regular season ended, clubs started signing futures contracts like crazy, whether they were practicing for the playoffs or taking part in their local golf league.

What are futures contracts, how do they work and which players have been signed to them?

Here's everything you need to know about these deals and how they'll impact your favorite team this offseason.

What's a Futures Contract?

It's the same as a regular active-roster contract, with the regular rules for minimum veteran salaries, cap charges, signing bonuses, etc. The only difference is that it doesn't take effect until the start of the next League Year (this year, that's March 11 at 4 p.m, per CBS Sports).

Teams can sign players to futures contracts as soon as the previous regular season is over, but the contract won't count against the salary cap or 53-man limit. Instead, it'll count against the salary cap and 90-man camp limit of the following season.

In the meantime, the player goes on the reserve/futures list and can't be signed by any other team.

Who's Eligible for a Futures Contract?

Any player who wasn't on an active roster at the end of the outgoing regular season, according to Andrew Brandt of NationalFootballPost.com. So, if a player was an unrestricted free agent or on any team's practice squad, after Week 17, they can be signed to a futures contract.

Here's the rub of the futures contract: For the most part, they're used on players who weren't quite good enough to justify an active roster spot this season but who teams think just might be worth an active roster spot next season. In many cases, this means teams locking up players currently on their own practice squad or another team's.

Brandt explained that this is a great way of locking up talented young guys on the cusp of breaking out. When he was vice president of the Green Bay Packers, he signed defensive lineman Cullen Jenkins, now of the New York Giants, to a futures deal.

Since practice-squad players can be poached by any team willing to sign them to an active contract, a futures deal ensures they'll be in the fold once OTAs and training camp roll around—peace of mind for front offices that would rather be concentrating on keeping its top talent and wooing key veterans at the start of free agency, not scrapping over players who may not make the team.

There's no limit to how many futures contracts a team can sign, as long as it will be under the 90-man roster cap at the beginning of the league year.

Technically, an unrestricted free agent like Terrell Owens would be eligible for a futures contract, but he'd be unlikely to agree to one.

Why? Well...

What are Futures Contracts Worth?

Typically, futures contracts are minimum-salary deals with little or no signing bonus. Most players signed to futures contracts will be fighting for a spot in camp; teams aren't going to invest much into players who may well be cut the following autumn.

Just as with any other free agent, teams can sign futures contracts above the veteran minimum—but rarely (if ever) do.

In 2011, the NFL Players Association filed a collusion suit against the NFL, alleging that teams were colluding to keep salaries down. One of their key pieces of evidence, Sports Illustrated's Michael McCann wrote, was a quote from Cincinnati Bengals head coach Marvin Lewis. Lewis and the Bengals lost a practice-squad receiver, Dezmon Briscoe, to the Tampa Bay Buccaneers after the Bucs offered him not a spot on the active roster, but a raise.

Paying Briscoe, now an active player on Washington's roster, $310,000 (instead of the prevailing $88,400 practice-squad salary) upset Lewis' apple cart.

"When you overpay a guy on the practice squad, you create a problem in the system for teams," Lewis said. "That's not the great precedent for teams to set as we try to keep the NFL doing the things we're trying to do as a league. It's still a league of 32 teams and things are put together a certain way."

That's all but admitting collusion—but due to the players agreeing to settle all past issues as part of the latest collective bargaining agreement, a federal judge denied the NFLPA's claim.

Going forward, it's worth wondering if NFL teams will ever start trying to outbid each other on futures contracts or if an exceptionally talented player finds himself unattached at the end of the season for some reason.

Who's Been Signed to a Futures Contract?

Rotoworld's Nick Mensio has been keeping an exhaustive futures contract signing tracker; go there if you want to see which players to whom your favorite team has extended the most cordial of an invitation to training camp.