"We are going to go with Nick and Alex to start with," Carroll said on Thursday. "The other guys are going to play and will be in early. It's a very good situation for us and those guy will all contribute."
Howell and Parsons followed up their impressive performances against Washington State with a solid week of practice and secured another week in the starting lineup.
"It just seems like it's the right thing to do after this week of work," said Carroll.
"Those four guys will all be battling over there and I know they are going to play hard, and play well," Carroll said. "They are determined to do that and they practiced well so we should get really good production out of that side."
Moala Rests, Will Play
Defensive tackle Fili Moala missed a good portion of practice Wednesday after injuring his ankle during pass rushing drills.
"My foot just clipped Charles' (Brown) foot and it just twisted my foot in the air and I came down on it on the side with all my weight," Moala said.
The senior defensive lineman, who is a key member of the Trojans defense, didn't practice on Thursday because of the ankle sprain but insisted that he would play against Arizona on Saturday.
"It feels pretty good. I'm playing Saturday with an ankle or not," Moala joked. "I'm playing no matter what.
"My team needs me and I need my team."
Moala will be called upon to help slowdown the Wildcats high-powered spread offense.
McKnight, Williams Ready for Action
Tailback Joe McKnight participated in drills at practice on Thursday and is expected to play this Saturday.
"Joe looked good. He was returning punts at the end here, going full speed," Carroll said. "Joe is ready to contribute and play in there."
After practice, McKnight said he is near 100 percent and ready to get back on the field and contribute after having to watch last week's game from the sidelines.
While McKnight didn't participate in any contact drills this week, he has stayed on top of the game plan.
"I have been taking my mental reps since Monday," McKnight said. "I'll be ready this Saturday."
Wide receiver Damian Williams was back at practice on Thursday after spraining his shoulder a day earlier.
Williams didn't appear to be limited by the injury and will play this Saturday.