As the San Francisco 49ers prepare to face a future Hall of Fame quarterback, it looks increasingly as if they will be without top cornerback Nate Clements.

The team acknowledged Friday that Clements underwent surgery earlier in the week to insert a pin and two screws into his thumb. Clements suffered a hairline fracture while tackling Buffalo running back Marshawn Lynch on Sunday and did not practice all week. He was officially listed as "questionable" on the team's injury report.

Clements, wearing a soft cast on his right hand, said he wants to play against Brett Favre and the New York Jets. But his mood was noticeably downbeat. Asked if there's a chance the injury would feel better by Sunday, he said: "Nobody's bone heals that fast."

Clements has yet to miss a game in his eight-year NFL career. His 124 consecutive games played trail only Tampa Bay's Ronde Barber (172) among active cornerbacks.

If Clements is unable to suit up, Donald Strickland and Tarell Brown are the top candidates to start in his place.

Coach Mike Singletary said that Clements' playing status would be a game-time decision. He added that when it's time to make a call, he will rely on the team's medical staff rather than the player.

"I don't even want to talk to Nate about it, OK, because I know how he feels. I know he wants to play," Singletary said. "That's not even a question."

At issue is whether playing would do further damage to the fracture. Clements is known for his physical style and it sounds unlikely that his thumb would withstand much of a pounding.

"It's jamming. It's falling on the ground. It's being able to protect yourself," Singletary said. "When you play this game, you can't be thinking about compensating because you'll hurt something else."

Clements said he never missed a game during three seasons at Ohio State or during his career at Shaker Heights (Ohio) High School.