Week 15 injury update: Adrian Peterson

Minnesota Vikings running back Adrian Peterson has not practiced since spraining his right midfoot in Sunday's game. While initial test results were encouraging, in that no significant damage was discovered, even a minor midfoot sprain can be problematic for a running back, as I noted earlier this week.

There is also concern about the risk of returning a player too quickly and suffering more significant damage, even from noncontact stresses such as planting and pivoting on the foot. According to ESPN.com's Ben Goessling, Peterson, who began the week wearing a walking boot, is now out of the boot but has been limited to exercising in a pool.

Toby Gerhart, who stepped in for the injured Peterson on Sunday but sustained an injury of his own, has been held out of practice due to a strained hamstring. Both players will attempt to return to practice in some capacity Friday, but Goessling notes that coach Leslie Frazier sounded more optimistic about Gerhart's chances than Peterson's. Given Peterson's initial reaction following the injury, his description of feeling his foot "pop a couple of times" and the location of the injury, all coupled with the fact he is still listed on the injury report with a groin ailment (as he has been for several weeks), it seems unlikely he will be unequivocally ready to play Sunday.

But this is Adrian Peterson, and assumptions when it comes to recovery and performance do not always apply. There should be more clarity with regard to his status by Friday afternoon. Peterson was not ranked by our experts this week, but Gerhart landed in the No. 16 slot of our aggregate rankings.