Another injury has ended another season for Sam Bradford. St. Louis Rams coach Jeff Fisher confirmed that Bradford tore his left ACL for the second straight year, meaning the quarterback will have missed nearly two full seasons (31 games) during the length of his rookie contract. Surely the "injury prone" label will shadow him for the rest of his career.

That's unfair.

The news is devastating to Bradford and the Rams, and it raises questions about whether the former Heisman winner will ever return to full health. He also suffered a shoulder injury in college (2009) and a high ankle sprain in his second NFL season (2011). But "injury prone" doesn't apply to Bradford any more than it applies to any other NFL player. There's no such thing as injury prone in pro football; there is only such thing as misfortune.

"I don't think you can call a clavicle fracture and ACL injuries and lump them together and call it injury prone," said orthopedic surgeon Derek Ochiai. "More like bad luck."

Sam Bradford hasn't played a full season for the Rams since 2012. (AP) More

In a league where behemoths like Cleveland Browns pass rusher Paul Kruger are always a step away, injuries of any sort are also that close. Kruger's hit put Bradford out of Saturday night's preseason game, and it looked about as normal as any other tackle of a quarterback. It didn't happen because Bradford left the pocket and didn't slide, or held the ball too long. It happened because Bradford was in Kruger's path. That's it.

That such an upsetting fate could befall Bradford is instructive as well as sad. Bradford is not a mobile passer. Neither is Tom Brady, who lost a season to a similar injury. Neither is Tony Romo, who has had chronic back issues. Neither is Peyton Manning, who has had four neck surgeries. Neither is Matthew Stafford, who had a series of shoulder injuries early in his NFL career, and was feared to be injury prone also. He too was mostly unlucky.

So is Stafford's teammate, Ryan Broyles, who was one of Bradford's favorite targets at Oklahoma. Broyles broke the FBS record for receptions in 2011, and has three season-ending injuries since: left ACL tear, right ACL tear and ruptured Achilles.

Granted, one ACL tear makes an athlete more likely to suffer another one – both in the same leg and in the other. But that doesn't get a player to "injury prone." Maybe "ACL tear vulnerable" is applicable. Bradford and Broyles are both of those things. But it shouldn't be a scarlet letter on either man in a league where vicious hits (or even standard hits) can't be legislated out. In a profession where pretty much everyone works year-round to stay in the best shape possible, those who stay off the injured list are blessed more by extra fortune than extra skill. Everyone has skill in the NFL; not everyone has gloomy fate.

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So the lesson is clear: every general manager better find and retain two starting-caliber quarterbacks. The Rams were smart to acquire Shaun Hill, who will probably take the reins in St. Louis after a backup career in San Francisco and Detroit. The Lions, meanwhile, have not replaced Hill and passed on chances to draft a good backup this year. If Stafford goes out again, the Lions' season is likely over (no offense to Kellen Moore). Meanwhile, San Francisco has invested a fortune in Colin Kaepernick, but now the Niners have the woeful Blaine Gabbert as a backup. They too are one hit away from a lost Super Bowl chance. The same can be said for the Dallas Cowboys and even the Seattle Seahawks.

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