Barkley, who suffered a bone bruise when his right shoulder was driven into the turf during the third quarter of the Trojans' 18-15 victory over Ohio State, was again held out of practice and unable to throw.
"He didn't have any restrictions at all, but it's a bone bruise, so it's sore, and it's just going to be that way until he can throw through it," Carroll said. "It's a matter of time. There's really not a whole lot they can do for it other than icing it and the normal range-of-motion things."
Barkley attempted to throw again on Wednesday but was unsuccessful.
"He did not feel great, or he would have thrown more. We're not going to blow it out here in practice trying to get him ready to see if he can throw," Carroll said. "If he had any discomfort at all we weren't going to throw yet, and we'll just wait until tomorrow."
Coach Carroll and Jeremy Bates both said they are in no hurry to make a decision on the starter for Saturday's matchup in Seattle.
"Here's what we know: We know that Aaron's put together a couple of really good days for us, and we know we're getting him ready to play," Carroll said. "We're going to wait and see how it turns out for Matt, and just wait it out."
"Matt's not practiced, and Aaron's our starting quarterback in practice right now," Bates said. "If Aaron's the guy, we're fired up."
Carroll added: "I was happy with the way Aaron's looked these couple of days. He's taken over just like he'd done in the springtime. It feels comfortable to us to have him getting ready."
All-American safety Taylor Mays also missed practice on Wednesday but did some work on the side with the training staff.
"He ran a little bit today. He's way better than he was yesterday. We'll go to the next day and see what happens," Carroll said. "We'll give him every chance to play on Saturday. It's a different situation than with the quarterback."
While the coaches will likely decide on a quarterback on Thursday or Friday, Mays, who has started in 40 consecutive games, could be a game time decision.
McKnight watched part of practice from the sidelines but was held out of practice because of migraine headaches.
- Offensive tackle Charles Brown returned from illness on Wednesday and will start at left tackle against Washington.
- USC quarterback Mitch Mustain did some punting at practice on Wednesday. Coach Carroll saw Mustain punt during the Trojans' walk-thru at Ohio Stadium last Friday and was impressed enough to have the third-string quarterback do some work today.
"Mitch hit a couple balls the other day that we saw. We're just giving him a shot to see what he looks like, give him a couple weeks to kick with us," Carroll said. "He's got a really good leg. It's going to take him a while, obviously, to get his timing down and all that."
When asked if Mustain would be given a shot to compete for the starting spot Carroll replied, " Not yet. We're going to see. We're going to give him a chance to see if he can develop a little bit. It would be a good thought, if he's traveling with us, that might help us somewhere down the road."
- With Taylor Mays' status still up in the air, Drew McAllister could see extended playing time this Saturday. McAllister, who missed last week's game with a hip flexor, practiced and is expected to be available on Saturday.
"He had a good day. He's into the plan, and he knows what he's doing," Carroll said of McAllister. "He's ready to play. And Josh (Pinkard) had enough turns there to help us with depth situations. We're in pretty good shape back there."
- Washington cornerback Quinton Richardson guaranteed a win over the Trojans following the Huskies win over Idaho. Carroll said the team was aware of the comments but he wasn't using them as motivation.
"There's nothing I can do about it. Those guys know. ... I heard them talking about it. I can tell them, ‘Don't listen to this' or ‘You didn't hear that,' but they're going to hear it and see it," Carroll said. "They're not going to make an issue of it, though. That's never been something I've ever engaged in in terms of motivation. It exists, and they know. They kick it around. That's not the kind of stuff we want to be motivated by. Does it work sometimes? Yeah, it does. But I don't operate with that."
- One-time USC commit Chris Polk is now a running back at Washington. Carroll said the Trojans liked Polk as a running back and wide receiver and would have used him in a similar role as Joe McKnight.
"We liked him as a tailback and a receiver. We thought he could do both. He was a good kick returner too, a really explosive football player," Carroll said. "We thought of him as a guy that would be in the role that we're using Joe."
Aaron Corp worked with the first-team offense on Wednesday. (Jaime Rodriguez Photo)
*Discuss more on the SCPlaybook.com message boards
If you have any questions, comments or suggestions you can reach Kevin Carden at firstname.lastname@example.org