The glaring stat comparison when evaluating this USC-Notre Dame matchup comes in the turnover department.

The No. 9/10-ranked Fighting Irish (4-1) are tied for second nationally in turnover margin (an average of +2 per game) and the Trojans (3-2) rank ... well ... tied for 122nd out of 130 FBS teams at an average of -1.4 turnovers per game.

USC has lost 13 turnovers through five games, including 3 interceptions each in its two losses -- which happen to be its only two road games so far -- at BYU and Washington.

And now the Trojans go on the road to South Bend, Ind., hoping they can reverse all of those aforementioned trends.

"I've stressed it every day to our kids, even today in our team meeting," USC coach Clay Helton said Thursday after practice. "In my 10 years here, the difference in this game has been the team that's played the cleanest football. The quality of players on the field are matched -- both teams have terrific football players -- but in my time here what's created the separation has been basically turnovers and penalties.

"I hit it right in the face today with our team, just giving them the history of my 10 years here and showing the games and showing when we win these football games, even on the road, these are games that you came out played great football, won your one-on-one matchups, but you played clean football. You won the turnover battle and you won the penalty battle and that's been the difference in these games."

Like last year.

USC put up 443 yards of offense in that 24-17 loss to the Fighting Irish, Helton noted, but the Trojans fumbled on two of their first five possessions. That included a promising second drive that reached the Notre Dame 33 on a reception by Michael Pittman, but the wide receiver lost the ball. And then late in the second quarter, Amon-Ra St. Brown caught a pass to take another potential scoring drive down to the Notre Dame 15, but he fumbled it while fighting for extra yards.

USC went into halftime with a 10-7 lead that could have been wider if not for those turnovers.

"Really the difference in the game was two turnovers to one turnover in a 24-17 ballgame," Helton said.

Earlier this week, offensive coordinator Graham Harrell made it clear he has no worries about Slovis -- the true freshman making just his second road start -- being affected by the environment at Notre Dame. He didn't feel Slovis' 3 picks in his first road game at BYU were the product of him being impacted by the moment -- just an off game, he said.

For that matter, Slovis also stated matter-of-factly that he didn't think road factors were to blame for his three picks in Provo, Utah.

"I don't think it makes a big difference whether I'm on the road or in the Coliseum, but just be disciplined, going through the reads, not letting the last play affect what I do the next time," he said.

Slovis is one of the most intriguing storylines this week, though, as he returns from a concussion having not played significant snaps since that BYU game a month ago (considering he was knocked out two plays into the Utah game the next week, sat out the Washington game and then had the bye).

Harrell suggested there might be some rust on his young QB, but Helton said Slovis looked sharp in practice and has had ample time to rebuild his timing with his wide receivers.

"He practiced last week and practiced without contact, but his timing and his accuracy and the chemistry with the receivers, he had a ton of time last week and this week has gotten a ton of reps. [He's] gotten about 75 percent of all the reps, so he looks really good," Helton said. "He looks like he's ready to go and has got a good confidence about him and seems on point with the receivers. It will be a great opportunity to watch him grow, to get back on the road after having a road experience and improve off that one."

-Helton said he does not expect sophomore safety Talanoa Hufanga to be limited after practicing in a yellow non-contact jersey all week to protect an AC sprain in his shoulder. Hufanga missed the Washington game with a concussion and the shoulder sprain.

"I think he's good to go. I talked to him today, he feels good with it, feels confident. We're just protecting any extra hits that he might take," Helton said. "You know, those AC sprains are painful and they're sore, but he's had three weeks and it's to a point now where he can go and he feels confident with it."

Helton offered more praise for his standout young strong safety, suggesting he will be an NFL player in time.

"What makes Talanoa so special is the extra work that he puts in. He wants to know everything and he studies everything," Helton said. "I think that's why you're going to see him playing on Sundays one day -- good Lord willing, staying healthy and continue to progress, he's got an extreme amount of talent."

Hufanga, who ranks second on the team with 42 tackles despite missing a game, discussed his shoulder and his season on Wednesday. Read that story here.

-USC will have an early morning practice/walkthrough on campus before its flight to South Bend, Ind.

-Helton announced that junior right guard Andrew Vorhees, who has missed the last three games with a foot injury, is undergoing season-ending surgery and redshirting. Vorhees was a starter the last two seasons, but he had been coming off the bench early this season behind starting RG Jalen McKenzie. Helton also suggested that senior linebacker Jordan Iosefa could be a redshirt candidate. Read more about both sitautions here.