SAN DIEGO -- While the resurgent Chargers waited word on the severity of Pro Bowl center Nick Hardwick's foot injury, All-Pro defensive tackle Jamal Williams underwent arthroscopic surgery on both knees Monday.

Williams had loose particles that had been bothering him flushed out.

The Chargers have their bye this weekend, and "with a little luck," Williams will be able to play when the Chargers host Houston on Oct. 28, coach Norv Turner said.

"Based on what our doctors said, it would have been hard for him to keep going," Turner said a day after the Chargers beat the archrival Oakland Raiders for the eighth straight time, 28-14 behind LaDainian Tomlinson's four touchdowns. "That's why we've rested him the last couple of weeks. We hoped we could get to this point; we did. I think this is really going to help him be ready to play at the same level he's been playing, over the next 10 weeks."

Williams has made every start this year, but has been held out of practice the last few weeks.

Hardwick, meanwhile, was having an MRI on his injured right foot. He was hurt on the seventh play from scrimmage, and the team said Sunday he had a sprain.

"There's concern," said Turner, who added Hardwick could be out three to four weeks.

"We don't know much yet," Hardwick said in a text message Monday evening.

Backup Cory Withrow played admirably in place of Hardwick.

"You can't say enough for Cory Withrow," Turner said. "I don't think he played a snap at center, then goes in and really played well. It's just a luxury when you have a guy who's capable of going in and doing those things, because obviously center, it goes a lot further than the physical things you have to do. Mentally, there's so many things you have to do, particularly when you're playing an eight-man-front team."

Withrow is an eight-year veteran in his second season in San Diego.

Turner also said wide receiver Eric Parker is getting a second opinion on his right big toe. Parker broke the toe during a June minicamp, and had surgery on it in early August. The Chargers said at the time they expected Parker to be out up to 10 weeks.

"We need to have a resolution on this at some point, soon, because if Eric's not going to make it back, we have to look and see if there's another direction," Turner said. "If he can make it back, we would love to get him back. This week, I think we'll have a little bit better feel, because we are being aggressive in seeing where he's at."

Copyright 2007 by The Associated Press