BERKELEY, Calif. — Kevin Riley will be California's starting quarterback at No. 23 Oregon State on Saturday in a defining game for both teams' Pac-10 hopes.

Although Riley and Nate Longshore both have been inconsistent this season for the Golden Bears (6-3, 4-2 Pac-10), Riley finally might have won over coach Jeff Tedford, even after a 4-for-16 performance in relief during Cal's loss at Southern California last weekend.

"His escape dimension and athletic ability gives you more options on offense," Tedford said Tuesday in his earliest midweek announcement of a starting quarterback since September.

Riley, a sophomore who grew up 80 miles from Oregon State's campus in suburban Portland, started six of Cal's first nine games, but briefly lost his job twice this season. Longshore started the other three games, including last week's 17-3 loss to the Trojans in Cal's lowest-scoring performance in Tedford's seven seasons.

Riley didn't start at USC after incurring a concussion against Oregon on Nov. 1, when Longshore played the final three quarters of Cal's 26-16 win. Neither quarterback was terribly effective against the Trojans' dominant defense, with Riley finishing with just 59 yards and the senior Longshore going 11-of-15 for 79 yards.

Riley made his first career start last year against Oregon State in Berkeley, but his inexperience helped lead to a disaster for the then-No. 2 Bears. Riley drove Cal well within field-goal range in the final minute of a 31-28 game, but the quarterback made an ill-advised attempt to run the ball with no timeouts, which allowed the clock to run out before the Bears could get their kicking team on the field.

"I thought he shook that off really well," Tedford said. "As a quarterback, you're going to run into those things. There are going to be times when you wish you had a play back here or there. ... I know that there was a lot riding on that play, but I think he did a good job of putting that behind him. I know he'll probably have to answer that question a lot this week, but I think that's pretty much in his past."

Tedford has been unable to make up his mind this season between Riley and Longshore, even giving the quarterbacks equal practice time with the first-team offense. The coach said Riley will get two-thirds of the practice time with the starters this week.

Tedford first benched Riley after a 42-7 victory over Colorado State, but yanked Longshore two weeks later during a loss at Arizona. Most of the quarterbacks' teammates have claimed the changes don't make a difference, but receiver Nyan Boateng respectfully disagreed Tuesday.

"In the middle of a game, when we switch quarterbacks like that, our timing gets thrown off a little bit," said Boateng, who has 23 catches for a team-best 367 yards and four touchdowns. "I think we need to find one guy and just stick with him."