Desman Stephens had played only a handful of snaps to this point, mostly in mop-up duty, but as the freshman linebacker peered over the line of scrimmage at Penn State’s offense Saturday, he could see the third-down play unfolding in his head. The Trojans had three over the ball. Two receivers were stacked to his left, and the nickel corner was blitzing. So Stephens knew, as soon as it was snapped, he needed to backpedal in a hurry to cover the middle of the field.

That part was no problem for Stephens, whose experience as a do-everything defensive back at Clarkston High in Michigan would serve him well in this situation. He was still learning the finer points of playing linebacker, though, still digesting USC’s defense under D’Anton Lynn. Every play still felt like it was flying by at warp speed.

But with linebackers dropping like flies off the depth chart, there was little choice but to trust that the true freshman could step in. And as depth all over USC’s defense continues to dwindle, it won’t be the last time that Lynn has to put his faith in a freshman.

Stephens, in this case, delivered on that trust in a big way, backpedaling into perfect position to pick off the Penn State pass. It was just the sort of play, Lynn said, that would pay dividends later for a defense that needs its defense to develop in a hurry.

“You can just tell,” Lynn said, “it gave him a lot of confidence.”

Lynn will take all the quick confidence he can get for a USC defense that now must weather the loss of two of its most consistent players: linebacker Eric Gentry and defensive end Anthony Lucas, both of whom were ruled out for the rest of the season this week. How exactly Lynn plans to navigate those losses remains to be seen, but it will undoubtedly involve an influx of young players, such as Stephens, thrust into much bigger roles along the defensive front.

Lynn and coach Lincoln Riley sold that as a positive this week, as USC travels to Maryland with hope that an infusion of youth on defense could help stop the Trojans’ two-game skid.

“We don’t really have a choice right now, right?” Riley said. “And these guys have been developing behind the scenes. They’re ready to contribute.”

Stephens has already cemented his place in USC’s three-linebacker rotation, playing behind starters Mason Cobb and Easton Mascarenas-Arnold, while junior Devan Thompkins emerged last week as a starter along USC’s defensive line, leading the group in pressures after Lucas left the game.

Kameryn Fountain could be next to step into that rotation up front. The 6-foot-6, 265-pound freshman defensive end is still “very, very” raw, but after turning heads in camp with his impressive physical prowess, Lynn said. Fountain has grown significantly in his understanding of his position and USC’s scheme, enough that “he is going to get some time” against Maryland this week.

“He’s gotten better trying to slow the game down for himself,” redshirt senior defensive end Jamil Muhammad said of Fountain. “It hasn’t all the way slowed down for him yet because he’s just now getting into the swing of things with things that happened health-wise.”

Adding young players up front could do USC’s pass rush good, given where it stands at the midway point. The Trojans have tallied just six sacks through six games — fewer than all but seven teams nationally — and just lost their leader in pressures, Lucas, for the season. Muhammad, USC’s leader in sacks last season, has yet to notch one in 2024.

There may not be a good answer to those problems right now. But Riley is confident, with Lynn on the job, that USC’s defense will be better for it in the long run.

“There’s going to be so many positives that come out of this for these guys and our program,” Riley said. “I do think D’Anton’s personality to teach and ability to be adaptable to 11 guys that we put on the field and their skill sets and also where they’ve got some deficiencies, I think that’s going to be a real advantage here.”

Muhammad has seen that progress for himself with USC’s new defensive staff.

“They’re all about throwing people into the fire, in a positive way,” Muhammad said. They want you to learn. They want you to get better. So I think you’ll have your opportunities as a young guy at a program like this. You just have to make sure you seize them, seize the opportunity.”

Stephens made the most of his moment last week, returning his interception 42 yards before he was taken down from behind. It was important validation, for the freshman linebacker, of where his first season at USC was headed. Even if the Trojans had no choice but to trust him.

“It was always big on my board to go to a place where I felt I could develop,” Stephens said.

“When you grind, you get rewarded.”