San Francisco quarterback Alex Smith folds under the pressure of a hit by St. Louis linebacker Jo-Lonn Dunbar on Nov. 11, 2012. Smith later left the game with a concussion.
Minnesota Vikings running back Adrian Peterson, left, runs past St. Louis Rams outside linebacker Jo-Lonn Dunbar on his way to a 52-yard touchdown run during the fourth quarter of an NFL football game Sunday, Dec. 16, 2012, in St. Louis. (AP Photo/Tom Gannam)
Minnesota Vikings running back Adrian Peterson, left, runs past St. Louis Rams outside linebacker Jo-Lonn Dunbar on his way to a 52-yard touchdown run during the fourth quarter of an NFL football game Sunday, Dec. 16, 2012, in St. Louis. (AP Photo/Tom Gannam)
San Francisco quarterback Alex Smith (folds under the pressure of a hit by St. Louis linebacker Jo-Lonn Dunbar earlier in the day. Smith and Chicago quarterback Jay Cutler suffered concussions and may not play when the Bears visit the 49ers on Monday night.
San Francisco quarterback Alex Smith folds under the pressure of a hit by St. Louis linebacker Jo-Lonn Dunbar on Nov. 11, 2012. Smith later left the game with a concussion.
