Carolina top receiver Steve Smith, Denver star linebacker Von Miller and St. Louis prized left tackle Jake Long all were forced to leave games Sunday because of knee injuries.
Also, Detroit cornerback Bill Bentley was being evaluated for a head injury after a frightening collision. He was able to walk off the field with some assistance.
Long was carted off the field after hurting his right knee on the Rams' first offensive series in a 23-13 win over Tampa Bay.
Coach Jeff Fisher said he thought Long tore a ligament, adding, ''We are anticipating the worst.''
Long's knee appeared to give out on pass protection against the Buccaneers' Adrian Clayborn. Long has started every game this season and was the first overall pick of the 2008 draft by Miami. He is finishing the first season of a two-year free agent deal.
Smith was hurt during a 17-13 win over New Orleans that clinched the Panthers' first playoff spot since 2008.
Smith was injured in the first quarter and tried to return in the second period but couldn't run on it. He's set for an MRI on Monday.
''They said it's nothing, but my knee doesn't feel like it's nothing,'' Smith said.
Miller left in the first quarter of a 37-13 win over Houston that clinched the AFC West for the Broncos. There was no update on his injury after the game.
There was a hush at Ford Field when Bentley was injured in the second quarter of the Lions' 23-20 loss in overtime to the New York Giants.
Bentley tried to break up a TD pass to Jerrel Jernigan, and appeared to be hit in the head by the arm of Detroit teammate Louis Delmas. Bentley was down on the ground for a few minutes before being helped up.
Green Bay linebacker Clay Matthews left a 38-31 loss to Pittsburgh after reinjuring his right thumb. He got hurt sacking Ben Roethlisberger in the second quarter and ran to the sideline.
Matthews missed four games after hurting the same thumb while making a sack Oct. 6 against Detroit.
Pittsburgh lost backup linebacker Terence Garvin to an injured left knee.
Last weekend, Garvin ended the season for Cincinnati punter Kevin Huber with a hit that resulted in a broken jaw and a cracked vertebrae. Garvin was fined $25,000 by the NFL for the play.