Rashard Mendenhall was hurt on the final play of the first quarter in a 13-9 win at Cleveland on Sunday, and coach Mike Tomlin made it sound as if the running back could miss the postseason.
"It's not good, of course, when a guy goes down in open grass and is not touched by anyone," Tomlin said. "Experience tells me that, in general, that's not good."
Mendenhall went down after a 5-yard gain and immediately grabbed his right knee. He walked slowly to the sideline, slapping hands with some teammates on his way to the bench and didn't return.
After the game, Mendenhall left the stadium on crutches, his head hanging in disappointment. Tomlin said Mendenhall would be examined when the team gets home.
"You should anticipate that he won't be participating next week," Tomlin said.
Mendenhall rushed for 38 yards on eight carries before getting hurt, giving him 928 yards this season.
Houston rookie quarterback T.J. Yates left the Texans' 23-22 loss to Tennessee after one series and was replaced by Jake Delhomme. Coach Gary Kubiak said Yates had a bruised left shoulder but could've returned if necessary.
"Obviously, I didn't want him to go back in the game," Kubiak said. "We'll know better where we're at (Monday) at this point."
The 36-year-old Delhomme, signed Nov. 29 in the wake of season-ending injuries to starter Matt Schaub and backup Matt Leinart, completed 18 of 28 passes, including a 5-yard touchdown pass to Bryant Johnson with 14 seconds left. Kubiak called for a 2-point conversion at the end. But after a false start penalty, backup center Thomas Austin snapped the ball over Delhomme's head and the game was over.
Denver lost two offensive starters in the first half of its 7-3 loss to Kansas City when right guard Chris Kuper broke his left leg and fullback Spencer Larsen hurt a knee.
"Chris Kuper is a very good friend of mine and to see what happened to him really put a damper on things," said Chiefs quarterback Kyle Orton, a former Broncos teammate. "He's a great teammate, a great leader on that team and I hope he's able to get back as soon as possible."
Kuper's replacement, Russ Hochstein, left in the fourth quarter with an undisclosed injury and Chris Clark replaced him.
Chiefs wide receiver Dwayne Bowe caught six passes for 93 yards in the first half, but sat out the second half with a neck injury.
Arizona quarterback John Skelton fainted in the locker room before leading the Cardinals to a 23-20 win over Seattle after getting fluid drained from a knee.
"Pre-game he scared us all. He fell out and he had a little fainting issue in the locker room," wide receiver Larry Fitzgerald said. "We were all nervous about him being ab le to play today and he fought through that and was able to go out there and perform and get our team a win. That shows the kind of toughness he has."
St. Louis quarterback Kellen Clemens injured his right leg on a sack by NaVorro Bowman with 2:46 to go in the Rams' 34-27 loss to San Francisco. He said X-rays were negative.
Miami wide receiver Davone Bess left the Dolphins' 19-17 win over the New York Jets in the fourth quarter with a right knee injury. Linebacker Karlos Dansby also went out in the first quarter with a groin injury, while guard Richie Incognito left in the third with a neck injury.
Washington's Brian Orakpo left the Redskins' 34-10 loss at Philadelphia with a left shoulder injury. He was scheduled to have an MRI on Monday.