The Steelers endured the nightmare of every NFL team that has clinched its playoff positioning: watching a star player go down with an injury.

Pittsburgh seems to have escaped the worst-case scenario, as quarterback Ben Roethlisberger is expected to be ready for the postseason after sustaining a concussion in Sunday's rout of the Cleveland Browns.

Roethlisberger was driven into the ground by two defenders late in the second quarter of an essentially meaningless game.

As Roethlisberger delivered a 4-yard pass to tight end Heath Miller over the middle, he was leveled by Willie McGinest at about shoulder level and D'Qwell Jackson at the quarterback's knees. Roethlisberger's head struck the ground hard as McGinest, possibly playing his final NFL game, drove him backward.

Roethlisberger moved his arms and legs and was talking before being placed onto a stretcher and then onto a cart that took him off the field. His helmet was taken apart while he was on the field, a precautionary move so his neck could be stabilized, but hospital tests revealed no additional injuries.

"All tests are negative — which is a positive," Steelers coach Mike Tomlin said. "We are optimistic of where he is going to be (in the playoffs). The bye is going to be helpful in regards to that."

As he was being driven off the field, Roethlisberger lifted his left arm and raised his thumb to the fans. The gesture drew a loud cheer from a crowd that remained silent during the nearly 15 minutes Roethlisberger stayed on the turf.

"When it starts taking long, you start to get worried and think something's going on, but we got the update from the trainers that he had a concussion," linebacker Larry Foote said.

The Steelers, already locked into the No. 2 spot in the AFC's playoffs, could not improve their playoff position by beating the Browns. But Tomlin wanted Roethlisberger and the other starters to play most or part of the game — the Steelers went on to win 31-0 — because they won't play again until Jan. 10 or 11.

Tampa Bay's Carnell "Cadillac" Williams scored two touchdowns before being helped from the field with a knee injury during the fourth quarter of the Buccaneers' loss to the Oakland Raiders.

Williams, who missed the first 10 games of the season after being sidelined more than a year with a career-threatening injury to his right knee, immediately grabbed his left knee when he was tackled at the end of a 28-yard run in front of the Bucs bench.

He was helped to the bench, where he pounded his hand in frustration and later limped to the locker room with help from team personnel. He finished with a season-best 78 yards rushing on 12 carries.

Houston Pro Bowl defensive end Mario Williams left the Texans' win over the Chicago Bears with a strained groin.

The 6-foot-7, 291-pound Williams came up limping on the third play of the second half, after Dominique Barber sacked Kyle Orton. Williams, the No. 1 overall pick in the 2006 draft, sacked Orton earlier and has 12 on the season.