No. 25 USC has begun preperations for its season opener Saturday against Minnesota.

• Redshirt junior guard Abe Markowitz and redshirt sophomore wide receiver De’Von Flournoy missed practice, while freshman runningback Amir Carlisle had to leave early. Coach Lane Kiffin said he is expected to be back tomorrow.
• Kiffin said on injuries, “We’re relatively healthy for the most part, which is good. We lost some guys for the season earlier in camp because of the hitting. But I think we’re more physical because of it.”
• Much of the talk was about Minnesota quarterback MarQueis Gray. A converted wide receiver, Gray was compared to Oregon quarterback Darron Thomas by USC junior safety T.J. McDonald. “It’s gonna be a good challenge,” McDonald said. “We gotta make sure when [Gray] gets outside the pocket we keep the pressure on their receivers.” McDonald also talked about the size of Gray, who’s listed at 6-foot-4, 230 pounds.
• “We can’t give him any second chances when we tackle,” McDonald said. “We gotta make sure to wrap him up and take him to the ground.” Kiffin also talked about the size of Gray, saying “He’s not just a mobile quarterback, he’s big, physical. He’s 240 pounds, so we’re gonna have our hands full here. … This is a very big challenge for our defense right off the bat.”
• Jerry Kill is entering his first season as Minnesota coach after spending three years at the helm of Northern Illinois. But Kiffin said it’s not any extra trouble having to watch both team’s game film.
• Kiffin reiterated Tuesday that no tailback has emerged as a clear starter but said that wasn’t a huge issue because “the goal coming into this game is to play a lot of guys.”
• Playing a lot of guys means there will be a lot of players getting their first-ever collegiate game experience on Saturday.
• “We say you’re a true freshman until you play,” Kiffin said. “Regardless of how long you’ve been here practicing. There’s gonna be a lot of big eyes Saturday. We gotta work through them, get a lot of guys in there, and see who’s ready to go.
• Kiffin said there was no update on senior defensive end Armond Armstead but was hopeful he might be cleared this week.
• The other major defensive injury — that of senior linebacker Chris Galippo — is also a point of concern. Galippo has participated in full the last two practices, but Kiffin said “I’m still nervous about it. This is a lot different that a real game. The tempo of the game, all the hitting. We’ll throw him out there and hopefully he’ll do well.”
• Finally, Kiffin said, although he feels more confident in his defense this year, he needs to see some on-field results. He said, “Until you play it doesn’t change very much. So I think even though we look better and we feel better and we’re bigger and stronger and faster and look like we tackle better, until we prove it it doesn’t matter.”
• Junior quarterback Matt Barkley goes up against the defense every day in practice, referring to it as “Savvy. They got a bit of swag,” Barkley said. “Especially the secondary. There’s a lot of leaders on this defense. … All those guys I think feel a lot more comfortable with the schemes and what they’re doing, where they can just play ball”