The ninth-ranked Trojans (5-1) have a deep stable of game-changing running backs with different skill sets the Irish (1-6) have to be aware of, and they're frequently rotated in and out of the game.
"When you're watching tape you see what type of running plays they like to run with each guy," fifth-year senior linebacker Joe Brockington said. He had a season-high 13 tackles in the 27-14 loss to Boston College last Saturday. "They're certain running plays and passing plays that they like to do with certain guys back there. That's all done pre-snap.
"We're going to have our hands full, that's for sure."
Unfortunately for the Irish, USC's leading rusher Stafon Johnson (46 carries, 378 yards, four touchdowns) and his ridiculous 8.2 yards per carry is practicing this week and could return from injury and play this weekend. Then there's Chauncey Washington (84 carries, 362 yards, six touchdowns) and freshman Joe McKnight (29 carries, 154 yards), this year's version of former USC standouts Lendale White and Reggie Bush.
"You go back to basic fundamentals and try to keep them inside and in front regardless of who it is," Irish defensive coordinator Corwin Brown said of how you stop them. "You want to come to balance when you get the opportunity to tackle them, and try to get as many guys as you can to the ball. That's what you're looking at more than anything else."
On top of that, it goes back to identifying which back is in the game before the snap.
"You have to think about who it is because from that standpoint some guys are faster, some guys run with more power, some guys when they get in the hole they're going to put their shoulder down, where others will give you a couple of moves," Brown explained. "Some guys like to hit the crease when they see it and some guys like to bounce it out. You have to kind of understand who you're playing against and be ready for that."
Booty, USC's starting quarterback missed last week's 20-13 victory over Arizona with a broken middle finger. Sanchez made his first-career start, completing 19-of-31 passes for 130 yards, with one touchdown and two interceptions.
However, unlike the running backs, Booty and Sanchez have similar styles so the Irish don't have to prepare for two different offensive looks. But with Booty, they'll have to be ready for more schematics.
"I think that Booty's experience expands the playbook," head coach Charlie Weis said. "I think Mark actually has probably a tad more athleticism, but I think any time you have the more experienced guy you can do more things. Obviously if they go with Sanchez, it's not going to stop their offense from running the same offense. I just don't think they'd do as much."
"You prepare for the system they run," Brown said. "It's not like one runs an option and the other one is a drop-back passer. It's the USC system you have to get ready for and that's enough to think about honestly."
***Since falling behind 23-0 at the half three weeks ago against Purdue, the Irish defense has played significantly better over the course of two-and-a-half games. The defense gave the team a chance to come back and beat the Boilermakers in a 33-19 loss, forced seven turnovers in a 20-6 win over UCLA, and played well enough to win last Saturday against Boston College.
Brown, who the players regularly call animated, has had to get on his guys a few times this year. In the locker room at Ross-Ade Stadium was one of those times.
"Well I think more than anything else, at some point you have to say enough is enough," Brown said. "I think everyone has to do that. Not just the players but the coaches."
"I think our whole team decided enough is enough," junior nose tackle Pat Kuntz echoed. "Even though we've still been losing, we've been giving it our all out there, I think we've been playing pretty competitive. We just have to keep it going through next week."
***One guy who keeps it going on a week-to-week basis is fifth-year senior defensive end Trevor Laws. He had 11 tackles against the Eagles and a blocked field goal. For the season, the 6-foot-1, 296-pound Burnsville, Minn. product leads the team with 58 tackles, 5.5 coming for loss.
"It's one of those deals where he comes out so hard, and he plays so hard and he puts everything," Brown explained. "Human nature is to have a letdown, especially when you're in a season like we're having. I've said it before. This is a different place and we have different kids. And he is just one of them. He's a senior. He comes out, and when I say he works, he works. And he plays. It's one of those deals, you're like that dude is still playing hard. He's spinning, he's fighting off blocks. It doesn't matter if he's playing against guys that are quote on quote the best, he's done it every week. That's encouraging and it gives the young guys something to see."
***Before the season, offensive line coach John Latina kidded Kuntz that he wouldn't bat down five passes this year. Up to this point, the 6-foot-3, 285-pound Indianapolis product has broken up a team-high seven passes.
"So I've been letting him hear it a little bit," Kuntz said. "He kind of challenged me a little bit so I laugh and joke around with him. I told him I'm going to double that this year."