...third quarter of an NFL football game against the St. Louis Rams on Sunday, Nov. 22, 2009, in St. Louis. Warner was taken out of the game after an injury in the second quarter...

Miami Dolphins' Ronnie Brown, center, is helped off the field with an ankle injury during third-quarter NFL football action against the Tampa Bay Buccaneers in Miami, Sunday, Nov. 15, 2009. (AP Photo...

Miami Dolphins' Ronnie Brown, center, is helped off the field with an ankle injury during third-quarter NFL football action against the Tampa Bay Buccaneers in Miami, Sunday, Nov. 15, 2009

...coach Eric Mangini yelling during an NFL game against the Detroit Lions, in Detroit. Mangini says he was frustrated at losing when he suggested the Detroit Lions faked injuries in Sunday's game. During his...

...sent a wide-ranging memo about concussions to NFL teams on Tuesday, Nov. 24, 2009, saying the co-chairmen of the league's committee on brain injuries have resigned and that he is examining potential...

...sent a wide-ranging memo about concussions to NFL teams on Tuesday, Nov. 24, 2009, saying the co-chairmen of the league's committee on brain injuries have resigned and that he is examining potential...

...coach Perry Fewell talking with an assistant coach during an NFL game against the Jacksonville Jaguars, in Jacksonville, Fla. With a rising amount of injuries, Fewell doesn't have much time to regroup as the...

FILE - These are 2009 file photos showing Green Bay Packers football players Al Harris, left, and Aaron Kampman. Green Bay cornerback Al Harris and li...

...third quarter of an NFL football game against the St. Louis Rams on Sunday, Nov. 22, 2009, in St. Louis. Warner was taken out of the game after an injury in the second quarter...

...Redskins offensive tackle Chad Rinehart (75) is carted off the field following an unknown injury by emergency personnel during an NFL football game against the Dallas Cowboys, Sunday, Nov. 22, 2009 in Arlington, Texas. The...

...fourth quarter of an NFL football game against the St. Louis Rams Sunday, Nov. 22, 2009, in St. Louis. Warner left the game in the second quarter after an injury, but Arizona went on...

...Betts (46) sits on the trainers table after having his left knee wrapped following an injury during an NFL football game against the Dallas Cowboys, Sunday, Nov. 22, 2009 in Arlington, Texas. The Cowboys...

...York Giants in the third quarter of an NFL football game, Sunday, Nov. 22, 2009, in East Rutherford, N.J. Turner is out with an injury. The Giants won 34-31. (AP Photo/Kathy...

...is carried on a backboard after suffering an injury on the final play of the Browns' 16-0 loss to the Baltimore Ravens in an NFL football game Monday, Nov. 16, 2009, in Cleveland...

...medical personnel treat wide receiver Josh Cribbs after an injury on the final play of a 16-0 loss to the Baltimore Ravens in an NFL football game on Monday, Nov. 16, 2009, in Cleveland...