BERKELEY, Calif. — Coach Jeff Tedford reopened California's quarterback competition today, giving equal practice time to Kevin Riley and Nate Longshore this week before choosing a starter for Saturday's game against Arizona State.

Not many teams averaging 445 yards and 43 points per game would be contemplating a quarterback change, but Tedford is wary of the Golden Bears' (3-1, 1-0 Pac-10) slow offensive starts in an embarrassing loss at Maryland and even last Saturday's 42-7 win over Colorado State.

With a looming visit from the Sun Devils (2-2, 1-0) that could have a big impact on both schools' hopes for a major bowl game, Tedford is acting aggressively to shake up Riley, the starter who struggled in last Saturday's start against the Rams.

"We need a little boost there," Tedford said. "We cannot afford to continue to wait and wait and wait for things to happen, so we need to find out who's the best guy to put us in a position to start a little faster."

Cal also will face Arizona State without starting tailback Jahvid Best. The school's leading rusher and receiver is out for at least one game with a dislocated left elbow. But while backup running backs Shane Vereen and Tracy Slocum have been outstanding in limited action, the Bears don't have a similar wealth of reliable options at quarterback.

Although Cal's offense is ranked second in yards and points in the Pac-10, the Bears' receivers haven't made many big plays for Riley or Longshore, who has played in three of Cal's four games this season as a backup.

Cal's offensive players have managed to avoid taking sides in the competition. Both players appear to be popular in the locker room, with teammates contrasting Riley's happy-go-lucky cool with Longshore's more businesslike demeanor.

"It's all about chemistry," said receiver Jeremy Ross, who caught his first career TD pass from Longshore against Colorado State. "We've got a lot of love for both of our guys, and we know they can get the job done. There's no choosing sides, because they're both talented. I'm comfortable with both of them in the huddle."

Tedford's reputation is built on tutoring a long line of superb passers, but he has spent most of the past 12 months without a clear-cut starter.

Riley, now a sophomore, played in Cal's season-crushing loss to Oregon State last year before taking over from Longshore and leading a bowl victory over Air Force. Riley then won another competition for the starting job this season by outplaying Longshore, the senior who was booed regularly during Cal's late-season collapse.

Longshore threw two interceptions in the opener against Michigan State, inspiring even more boos — but then it was Riley's turn to struggle. The bleary-eyed Bears fell behind 21-3 at Maryland in a game that started at 9 a.m. Pacific time, and a late rally couldn't stop a 35-27 upset loss.

Riley went 6-of-13 for 59 yards and an interception in the Bears' slow start against Colorado State, and the offense made just one scoring drive in the first three quarters. Longshore replaced him and went 9-of-13 with two TD passes, but only after the game was pretty much decided.

"He understands he's missed some balls," Tedford said of Riley, who didn't make his usual appearance at Cal's weekly news conference. "We'll evaluate it throughout the week of practice. It's no different to any other position."

Despite Tedford's indecision, the rest of the Cal offense seems unworried about who's lined up under center Alex Mack.

"The only difference for me is on the snap, but I've done that so many times with both of them," Mack said. "We've flip-flopped so many times over the last year and spring ball that I don't think it's a problem."