USC doesn't plan to hold back on offense

USC regards today's mock game at the Coliseum as a dress rehearsal for next week's season opener against San Jose State.

It's also a coming out of sorts for Matt Barkley.

The freshman quarterback made national headlines after Coach Pete Carroll on Thursday chose Barkley over Aaron Corp as the Trojans' starter.

So the curiosity factor is high for fans coming out to catch a glimpse of USC's officially stamped present and probable future.

Barkley is hoping for a better performance than his last one at the Coliseum.

On Aug. 17, a week after Corp suffered a leg injury that ultimately doomed his chance to start, Barkley had an opportunity to take over the quarterback competition.

Instead, he threw his first pass into coverage and stumbled through a five-for-18 passing night.

Barkley has since shined at times, but he also has struggled at others with touch and interceptions.

That's not unusual for a young quarterback, but it could be problematic for a USC program that puts a premium on taking care of the ball.

"We're not making any concessions because he's a freshman," Carroll said.

Barkley, of course, is no ordinary freshman. He understands the offense better than Matt Leinart, John David Booty, Mark Sanchez or Corp did in their first training camps.

However, one of Barkley's greatest strengths is also one of his potential liabilities: his instinct.

The 6-foot-2, 230-pound Barkley wants to make plays. Checking down to shorter routes and throwing the ball out of bounds when necessary go against his nature.

"It hasn't been how I've played in the past, so I'm molding myself to fit this role," Barkley said.

Barkley was a four-year starter at Santa Ana Mater Dei High, where he was, to use Carroll's word, a "centerpiece" player. His high school team counted on him to make plays.

The result often was impressive. Barkley passed for 35 touchdowns and was the Gatorade national player of the year as a junior. But he also had 18 passes intercepted as a senior.

"He trusts himself and believes in himself so much that there are times when he's going to fire the ball and it's going to be close -- and the decision could be made more conservatively," Carroll said.

"I think that's why he's a great player too, though. That's part of it. We'll try to work our way through that."

Carroll and new quarterbacks coach Jeremy Bates have preached patience, instructing Barkley to consider himself a piece of the offense, not the entire operation.