LOS ANGELES – Not many young quarterbacks would even have the audacity to imagine making their first career starts under the circumstances surrounding Max Wittek at the Coliseum on Saturday night.

The freshman is replacing Matt Barkley, an injured senior who has claimed most of the career passing records at Southern California. He’s facing Notre Dame (11-0), a storied football power with a No. 1 ranking and the nation’s most feared defense.

The Irish need just one more win to book a spot in the national title game, and the struggling Trojans (7-4) have lost three of their last four. Yet Wittek also has arguably the best receiving duo in the nation catching his passes and a sold-out stadium firmly at his back.

If the enormity of this occasion is scaring Wittek, the confident 19-year-old with a bigger arm than Barkley hasn’t shown it a bit.

“You really can’t ask for a better opportunity to show what you’ve got,” Wittek said. “I just want to get that first snap, maybe that first hit, out of the way, and I’ll be ready to go.”

The Irish are just one win away from completing a remarkable run to the BCS title game in Coach Brian Kelly’s third season. “

USC is headed to a lower-tier bowl game, but could halt its late-season slide from the preseason No. 1 ranking by crushing the Irish’s title dreams. USC has stumbled after a 6-1 start to a season of enormous expectations, losing to Arizona, Oregon and UCLA in the previous four weeks.

“This is a game where we can get our respect back and get a good feeling about ourselves,” USC safety T.J. McDonald said.

Wittek has played only sparingly this season, but has known he would be under the spotlight this week since the injured Barkley texted him after last week’s loss: “Let’s go beat the Irish.”

After two full years of practice in Kiffin’s offense, Wittek is eager to show the Trojans won’t have to keep it simple as they did two years ago, when backup Mitch Mustain filled in for the injured Barkley in Notre Dame’s 20-16 win at the Coliseum.

“They’re a great defense, obviously one of the top defenses in the NCAA, but every defense does have their soft spots,” Wittek said. “Theirs are obviously limited in being such a great defense, but we are looking forward to taking advantage of some of those soft spots.”

Wittek’s confidence doesn’t seem so outlandish given the talent around him: receivers Marqise Lee and Robert Woods, along with tailbacks Curtis McNeal and Silas Redd. Wittek’s teammates are completely familiar with the quarterback who got about 25 percent of the first-team snaps in practice this year — and he’s superior to the decorated Barkley in at least one area.

“Max throws much harder. It hurts,” Lee said with a laugh. “I have faith in Max. I know he can do it. It’s about waiting for your time, and his time is here.”

If the Trojans can crack Notre Dame’s vaunted defense, the Irish offense will be required to produce a big game against USC’s struggling defense. USC’s last four opponents have combined for 156 points, and Notre Dame quarterback Everett Golson is coming off a 346-yard passing performance against Wake Forest — the seventh-biggest in school history, accomplished in just two quarters.

But every number in Notre Dame’s favor won’t matter when the Trojans go after a historic upset in a rivalry series full of unexpected twists. The Irish understand the perils looming in those 60 minutes before they earn the right to play for another national title.

“It’s very exciting,” Notre Dame center Braxston Cave said. “This is what guys come to Notre Dame for. We’ve finally got the program back to where it belongs, and I think guys are really excited about that.”