The NFL is predicated on a game of violence.
For 60 minutes, the world's greatest athletes pound on each other for our viewing entertainment.
But with that violence comes the reality of injury, and in the NFL, it comes at a rate that far exceeds most other professional sports.
The 2011 season was no different, as a number of NFL stars were lost for significant periods of times with catastrophic injuries. That list includes the likes of Minnesota Vikings running back Adrian Peterson, who got his knee twisted up late in 2011 and tore a number of ligaments.
Leading into next season, there are still major concerns about players rehabbing those injuries, including Peterson.
In the following slides, we'll breakdown the players who still have concerns ahead of the 2012 season.