Kevin Prince sits out another practice

It appears increasingly likely that UCLA will face the nation’s top-ranked team with its second-string quarterback.

Kevin Prince, who has started five of the Bruins’ six games, sat out a second consecutive practice Tuesday as he awaited the results of two MRI exams on his injured right knee.

The first MRI was performed by UCLA’s medical staff and the second by a doctor who performed surgery on Prince’s knee during his senior season at Encino Crespi High.

Coach Rick Neuheisel said Prince’s status for the Bruins’ game against No. 1 Oregon on Thursday at Autzen Stadium would be a game-time decision.

“He wants to play, thinks he can play,” Neuheisel said. “We’ll just have to wait and see.”

Sophomore Richard Brehaut took most of the snaps during a wet practice, with Prince standing on the sideline in shorts and a jacket signaling plays. Third-stringer Darius Bell also participated but mostly handed the ball off.

Brehaut would be making his second college start if Prince is unable to play because of an injury he initially suffered against Texas on Sept. 25.

In his first start, against Washington State on Oct. 2, Brehaut completed 12 of 23 passes for 128 yards during the Bruins’ 42-28 victory. He didn’t have a touchdown pass or an interception but ran for a one-yard touchdown.

“Nothing’s too big for Richard, so I’m not concerned that he’ll be overwhelmed,” Neuheisel said. “If they overwhelm us, it will be because they overwhelm us, not because Richard’s not ready for that.”

Though he acknowledged some concern with the thought of Prince starting during a week in which he had missed multiple practices, Neuheisel said such a move was not unprecedented in his coaching career. Koy Detmer did it when Neuheisel was at Colorado and Marques Tuiasosopo shrugged off a bruised hip and buttocks to help Neuheisel’s Washington Huskies defeat Arizona in 1999.

“Marques Tuiasosopo went a whole week without practice when we went down to Tucson and he came in and helped us win the game,” Neuheisel said. “I’ve been around that. You have to have experienced guys, but I think Kevin is experienced.”

Ayers healing

Linebacker Akeem Ayers said this week was the best he felt since a shoulder injury knocked him out of the Texas game.

“The first two weeks felt the same,” Ayers said. “Playing some defensive end required I really use my shoulder. It was getting aggravated. But the bye week has given it a chance to heal.”

Ayers’ speed and aggressiveness has produced strong moments against the Ducks the past two seasons. As a sophomore, he chased down Ducks quarterback Jeremiah Masoli from behind. Last season, he made a leaping interception in the back of the end zone, coming down with his feet inbounds for a touchdown.

Oregon injuries

Running back Kenjon Barner (concussion), defensive back Anthony Gildon (left ankle injury), defensive tackle Zac Clark (leg injury) and defensive end Terrell Turner (left leg injury) sat out practice Monday.

ben.bolch@latimes.com

chris.foster@latimes.com