Every year in the NFL, there seems to be at least one significant injury to an important player during the summer, whether that’s in drills at training camp or in preseason game action.

One wrong move or one bad hit can cause a team’s entire season to be throw into disarray, as well as change the future of the injured player. Just last week the Los Angeles Chargers suffered a huge blow as star cornerback Jason Verrett suffered a freak season-ending Achilles injury in a conditioning test.

Here are five noteworthy preseason injuries in NFL history that were massive at the time, but became even more momentous in hindsight.

Trent Green, St. Louis Rams, 1999

If it wasn’t for Green tearing ligaments in his knee on a hit by Rodney Harrison in a preseason game, the Greatest Show on Turf may have never been born. With the Rams’ starter knocked out, in stepped the little-known Kurt Warner, who picked up the MVP award and guided the team to their first Super Bowl title.

Ryan Leaf, San Diego Chargers, 1999

Though he’s known as one of the biggest busts in NFL history, the No2 overall pick was the victim of bad luck in his second season, which he missed entirely after tearing the labrum in his throwing shoulder during a workout in training camp. After recovering, Leaf made just 12 more starts in his brief career.

Teddy Bridgewater, Minnesota Vikings, 2016

Just when it seemed like Bridgewater was about to take the next step in his third season, a non-contact dislocated knee and torn ACL in practice ended his campaign before it even got off the ground. The former top prospect had attempted all of two passes since and is now trying to revive his career with the New York Jets.

Tony Romo, Dallas Cowboys, 2016

No stranger to crunching hits during his playing days, Romo was seemingly always playing hurt. But a broken bone suffered in his back during a preseason game against Seattle forced Romo to relinquish the job to rookie Dak Prescott, who never gave it back. After the young gun took over, Romo threw just four more passes before heading into the TV booth.

Darryl Stingley, New England Patriots, 1978

One of the most devastating hits in the league’s history just so happened to come in a meaningless preseason game in 1978 when Oakland Raiders safety Jack Tatum levelled Stingley, leaving him a quadriplegic. A truly sad moment that changed the course of history in the worst possible way for the Patriots receiver, who died at the age of 55 in 2007.