"It all went as expected," Sooners coach Bob Stoops said. "The doctors were pleased and had nothing that was surprising. It all went the way it was supposed to."

Williams started three of No. 3 Oklahoma's first four games and had recorded one sack and four tackles for a loss before he was injured in the third quarter of last Friday's game at Tulsa. He also suffered a season-ending injury in 2005, when he tore a knee ligament in the opening game against TCU.

"It's just unfortunate. He was playing so well here," Stoops said.

Stoops said it was "just too soon to know" whether Williams, who is scheduled to graduate in December, will seek a sixth year of eligibility.

Alonzo Dotson, who started against Miami, is expected to fill Williams' defensive end position opposite Auston English on Saturday at Colorado.

"We've got other guys that are used to playing," Stoops said. "Alonzo Dotson and Auston English have been playing great. Alan Davis, Jeremy Beal, those guys have got to step up and take over in those spots, and they're more than capable."

Stoops said Chris Brown, who's been splitting time at tailback with Allen Patrick and DeMarco Murray, was able to go through conditioning and could return against the Buffaloes after smacking the back of his head on the turf against Tulsa.