Walker and Graf will switch -- for the week

So Aundrey Walker is going to get his chance at left tackle.

The 6-6, 320-pound sophomore worked exclusively at the position in practice on Tuesday, switching over from the right tackle spot he started at in the first week of spring practices earlier this month. And redshirt junior Kevin Graf, who worked at left tackle during the first week, took Walker's spot on the right Tuesday.

Trojans coach Lane Kiffin said it was another experimental move meant to take advantage of the spring season and give Walker a chance to prove himself at the primo position. If it doesn't work out, then both players will switch back and presumably stay there all season. If it works out great or works out some, then Walker could get additional chances later this spring and in the fall.

"It's spring and it's early," Kiffin said after Tuesday's practice. "Let's see what it looks like."

Kiffin said the decision had nothing to do with Graf's first-week performance on the left side but did note that he began to feel comfortable toward the end of the 2011 season at right tackle. The coach has expressed confidence in Walker's abilities this spring because of the 19-year-old's natural abilities and extreme weight loss.

The plan now is to have Walker stay on the left for Thursday's practice and Saturday's scrimmage and then reevalute both players' performances on Sunday in film review.

"We went through three days the other way," Kiffin said. "Let's go three days this way and then assess it and see where we're at.

"We'll look at the same thing again by next Sunday and figure it out."

Kiffin and USC also moved linebacker Tre Madden to running back on Tuesday in what could be a temporary or long-term switch. Last spring, the Trojans moved safety Dion Bailey to linebacker, and that ended up working out quite well.