In quest of another opinion, Washington Redskins quarterback Doug Williams is in Los Angeles today to see the renowned knee specialist, Dr. Robert Kerlan. According to sources, one doctor already has recommended that Williams have arthroscopic surgery next week on his injured left knee, and Kerlan is expected to concur.

Bubba Tyer, the Redskins' trainer, said yesterday that a formal announcement on the surgery won't come until today, after Kerlan confers with Williams and Redskins physician Charles Jackson, who examined Williams' knee last Friday. Dr. James Andrews of Birmingham, Ala., saw Williams on Monday. Andrews, one of Williams' old friends, was in favor of surgery, sources said.

Andrews, reached in Birmingham yesterday, deferred all comments to Tyer, who said if Williams does have the surgery, it shouldn't "be anything serious."

Tyer added: "Doug just has a rough, arthritic knee from previous injuries. We're not anticipating any major reconstruction or anything like that."

Generally, arthroscopic surgery is quick and relatively trauma-free, and a source close to Andrews said Williams probably needs only to have the knee "cleaned out." Tyer said the results of arthroscopic surgery vary, and it would be impossible now to pin down how long Williams would be sidelined.

In the meantime, a source close to Andrews said: "He got the knee bent back under him, and it's sore and there's swelling. Nothing that could affect his playing next year. He'll be fine. He's been playing with this knee for years and has been doing great."

If Williams passes on surgery, he simply would rehabilitate the knee with help from Tyer and assistant Redskins trainer Keoki Kamau. If he has the operation, he would pick his own doctor, though the Redskins have to pay all costs. While Andrews is one of Williams' old friends from his days with the Tampa Bay Buccaneers, Kerlan is a friend of Redskins owner Jack Kent Cooke.

"{The doctors} will all communicate, and Doug'll make the decision on what he needs to do," Tyer said.

Williams was unavailable for comment.

In another development, defensive tackle Dave Butz, 37, said he's "leaning" toward coming back next season, which would be his 15th. He said Coach Joe Gibbs and the rest of the staff are reviewing film of the 1987 season, and he kind of assumes they want him back, though he's not absolutely sure.

"I asked Gibbs after we lost to the Giants {in the 1986 NFC title game} whether he wanted me back, and he said he had to watch the films," Butz said yesterday. "So this time, I didn't ask."

Meanwhile, one of Butz's old friends, former Washington quarterback Joe Theismann, said yesterday that the Redskins' defensive philosophy of constant substituting is perfect for Butz. "He can play one or two downs and be spelled," Theismann said. "It keeps him fresher. He's as integral a part of the team now as he was all those years ago."

Redskins Notes:

Defensive lineman Markus Koch has a broken bone in his wrist and is wearing a cast, though Tyer does not consider the injury serious . . . Joe Bugel, Redskins offensive line coach who recently interviewed for the Los Angeles Raiders head coaching job, said the Redskins front office did not offer him a raise to stay in Washington. On the other hand, Bugel wasn't expecting a raise and said he's just happy "to be a Redskin." On the subject of Al Davis -- the Raiders' managing general partner -- Bugel said he'd heard all sorts of stories about how Davis interviewed assistant coaches for the sake of milking them for information. Bugel said he'd even heard that the room might be bugged in case he slipped and gave away any information. So, when Bugel went out to Los Angeles for the interview, he asked Davis about it, and he said Davis just laughed. Incidentally, Bugel says that when Davis called Coach Joe Gibbs to ask for permission to speak with Bugel about the job, Gibbs told Davis: "Al, just don't bring him out there for a clinic, all right?" Gibbs said it's a true story, but he was only kidding.