Cowan to start at quarterback

UCLA will go with the quarterback who has beaten USC, though whether he is the one who finishes the game against the Trojans is to be seen.

Patrick Cowan, who ran the offense last season in a 13-9 victory over the Trojans, will start Saturday, Coach Karl Dorrell said Thursday. But Dorrell did not rule out using Ben Olson in a game the Bruins probably have to win to save Dorrell’s job.

“Ben I think is going to be up and ready to play,” Dorrell said. “He’s not 100%, but he is much further along than last week. We’ll see how the game unfolds.”

Olson, who had sat out four games because of a knee injury, played the second half against Oregon last Saturday. Olson said after the Oregon game that he expected to start against USC, but that “the decision is not mine to make.”

Cowan, who hasn’t played since suffering a collapsed lung against Arizona on Nov. 3, helped give the offense a jolt, allowing the Bruins to score enough points to upset the second-ranked Trojans last season.

He threw for only 114 yards in the game but had 55 yards on four scrambles during the Bruins’ 91-yard drive for their only touchdown. Cowan scored on a one-yard run.

“His mobility was the determining factor,” Dorrell said.

Dorrell said that Osaar Rasshan would be another option. The Bruins need to beat USC and have Arizona State lose to Arizona to reach the Rose Bowl.

A Rose Bowl berth is believed to be the only way Dorrell can ensure his return next season.

This is the second consecutive year Olson has entered the season as the No. 1 quarterback and his season has been interrupted by injuries.

He played in only five games in 2006 before sustaining a torn medial collateral ligament in his left knee.

“Life is interesting, definitely,” Olson said about being injured two consecutive seasons. “You just have to make the most of the situation. I have learned through experience that it doesn’t do any good to worry about things you have no control over.

“It has been tough in a lot of ways. We haven’t had the type of season that we would have wanted as far as a team. For me, personally, it hasn’t gone the way I envisioned it would go. You have to dust yourself off and keep going.”

Olson, a former Brigham Young player considered the top recruit in the nation when he came out of Thousand Oaks High in 2002, has one season of eligibility remaining.

Tailback Craig Sheppard’s availability will be a game-time decision. He has not practiced this week while recovering from a groin injury.

Sheppard, a walk-on who was the Bruins’ No. 2 tailback against Oregon, has the last two touchdowns scored by the Bruins’ offense, a two-yard run against Arizona State and a 20-yard run against Oregon.

“He felt better today and did some drill work on the side,” Dorrell said. “The trainers wanted him to get another day of rest.”

If Sheppard can’t play, Chane Moline and Christian Ramirez will backup starter Chris Markey.

Junior tailback Kahlil Bell, who sustained a torn anterior cruciate in his right knee against Washington State on Oct. 27, will have surgery Tuesday. Bell, who remains the Bruins’ leading rusher with 795 yards, probably will not be ready for spring practice.

chris.foster@latimes.com