LOS ANGELES — Southern California quarterback Mark Sanchez did some work in practice Wednesday, giving the Trojans hope that he'll be able to play against Arizona State on Saturday at the Los Angeles Coliseum.

"Much better today," USC coach Pete Carroll said.

"Dramatic improvement," was offensive coordinator Steve Sarkisian's opinion.

Sanchez suffered a bone bruise in his left knee in the third quarter of USC's 44-10 victory over Oregon last Saturday.

"He threw the ball really well and practiced really well," Carroll said. "This is what the doctors hoped he could do. We'll see what happens after today's work. If he's no worse off, he'll practice the whole practice tomorrow, or the majority of it."

Sanchez, in his first full season as USC's starter, has already been selected the Pac-10 offensive player of the week three times this year, having thrown for 1,069 yards and 13 touchdowns.

"We didn't put too much on him today, we'll see how he reacts tomorrow," Sarkisian said. "Some guys come back in three or four days (from this injury), some guys in a couple weeks. He didn't do anything yesterday. I thought he threw the ball well. I still think it's day to day. If he can't come back and practice tomorrow, we're back to square one."

If Sanchez can't go, he'll be replaced by Mitch Mustain, a sophomore transfer from Arkansas who completed 5 of 8 passes for 111 yards and a touchdown with an interception against Oregon.

Carroll also said linebacker Rey Maualuga, who didn't play against Oregon because of a sprained knee, was much better and on track to start against ASU.

Fullback Stanley Havili, who suffered a neck strain on the final play of Tuesday's practice, didn't participate Wednesday, and tailback Joe McKnight tweaked an ankle, but both are expected to play Saturday.

"We're practicing like crazy," Carroll said. "We had a really good practice today — one of the best days we've had."

The Trojans (3-1, 1-1 Pac-10) have won eight straight games over ASU (2-3, 1-1), including a 44-24 decision last November. The Sun Devils bring a three-game losing streak into the game, having scored only 44 points in losses to UNLV, No. 10 Georgia and California.

ASU quarterback Rudy Carpenter, who sprained his left ankle in the loss at Cal, is questionable for Saturday's game. If he can't play, junior Danny Sullivan will get his first career start. Carpenter has started 36 straight games for ASU — the second-longest active starting streak by a quarterback in the country.