In an ideal world, no player would ever lose his job over an injury. But in reality, players get injured all the time, whether it's during a game or even the offseason, and someone has to step in to replace them. Sometimes it's temporary, and sometimes it's not.
Even big names can lose their spots if they stay injured too long. Victor Cruz was one of the hottest names in the NFL until the injuries started piling up. After playing in just six games last season due to a leg injury, he has yet to return to practice and his future in the league is murky at best. In 2012, Alex Smith suffered a concussion with the San Francisco 49ers and was told he wouldn't lose his job due to the injury. Despite Smith's 6-2-1 record as a starter that season, Jim Harbaugh switched to Colin Kaepernick permanently.
The most famous example happened with the New England Patriots in 2001. Established starting quarterback Drew Bledsoe was knocked out of a Week 2 game and in came little-known Tom Brady. Bledsoe was cleared to return later in the season, but head coach Bill Belichick stuck with Brady. That worked out pretty well for both of them: Brady ended up leading the Patriots to a Super Bowl win, the first of four he and Belichick have enjoyed together.
Bledsoe, on the other hand, finished his career in Buffalo and Dallas, never making it back to the playoffs.
An injury that helps bring about one of the greatest careers in NFL history doesn't happen very often. Injuries that change the course of a player's career or a team's season are much more common. This season, several players could already be facing their last chance, injury-wise, with their current teams.
Tony Romo, QB, Dallas Cowboys
Tony Romo has been the Cowboys' franchise quarterback since 2006. His play has been consistently strong outside of a few lowlight-reel turnovers over the years, with more than 34,000 career passing yards and 247 touchdowns.
But he's 36 years old, and injuries have limited him to fewer than 16 games a total of five times over the course of his career. More significantly, Romo hasn't played a full 16-game season since 2012. No injury hurt a team more than when Romo went down with a broken collarbone last season. The Cowboys went 3-1 with Romo under center but were a complete mess without him, going just 1-11 in his absence.
That led to speculation that the Cowboys would select one of the top two quarterbacks in this year's draft, either Jared Goff or Carson Wentz. However, Goff and Wentz were both off the board when the Cowboys picked fourth overall. They reportedly wanted to trade up for Paxton Lynch, but got outbid by the Broncos. Instead, Dallas waited until the fourth round to draft a quarterback, where they took Dak Prescott out of Mississippi State.
But if he struggles after his latest collarbone injury, or if he can't manage to stay healthy, Romo's time with the Cowboys could be winding down.
Jason Pierre-Paul, DE, New York Giants
There may not be any other player in the NFL with more to prove than defensive end Jason Pierre-Paul. At the beginning of his career, he looked like he might be a first-round bust before breaking out the next year as one of the most talented pass rushers in the league. He was on his way to a huge contract with the Giants when a fireworks accident mangled his right hand and forced him to miss the first half of the 2015 season.
In limited action last season, Pierre-Paul had to wear a club on his hand and will now need to wear a special glove for the remainder of his career. He looked fast and agile last year, but he missed several tackles and potential sacks when he was unable to grab onto opposing players. He signed a one-year deal worth $10 million, which is huge, but he still only has security for the one year and will need to re-establish himself as a top-tier pass rusher this season.
Ryan Clady, LT, New York Jets
Ryan Clady has a lot to prove after he was traded by the Denver Broncos to the Jets. He's coming off a torn ACL and has missed 30 regular season games over the past three years due various ailments including a Lisfranc injury and shoulder surgery. When healthy, though, he has found a ton of success -- Clady is a four-time Pro Bowler and has been named an All-Pro three times.
He'll need to find that success again. With a $10 million team option for 2017, Clady has to show the Jets he can replace the recently retired D'Brickashaw Ferguson. Money was the main reason the Broncos traded him, and his pay this season is already down to $6 million from the base $9.5 million he was set to make before the trade. Clady is losing money at this stage, and he'll need to return to Pro Bowl form to earn it back. The first step, however, is staying healthy.
Antoine Bethea, SS, San Francisco 49ers
Donte Whitner revitalized his career with the San Francisco 49ers, so much so that many were upset when the team let him walk two years ago and signed Antoine Bethea as his replacement. Bethea was considered an over-the-hill coverage safety, incapable of delivering the hard-hitting, aggressive level of play that Whitner managed while wearing the red and gold.
But Bethea surprised everyone with four interceptions, 10 passes defensed, 86 tackles, a sack and a forced fumble in 2014, his first season with the team. He made the Pro Bowl that season as well, his first since 2009 with the Indianapolis Colts. He picked up where he left off in 2015 until his season was cut short due to a torn pectoral muscle.
His replacement last season, Jaquiski Tartt, performed quite well and also has youth on his side. Tartt is just 24 years old, while Bethea will be 32 when the regular season comes around. Bethea will likely be battling Tartt right out of the gate for playing time, and if he doesn't prove that he can still play at a high level, he may find out that he has already been replaced.