High, shortly after his high school coach yanked him up to varsity after a single half of JV ball.

One glance at Jackson, and it doesn’t seem the former three-star back is exactly a hand-in-glove fit in Riley’s scheme. The head coach hasn’t deployed a back of Jackson’s sheer size since he had 231-pound Rhamondre Stevenson at Oklahoma in 2020. For the past two years, from MarShawn Lloyd to Marks, USC’s running backs have largely thrived off cutbacks and pockets in a spread-out offense. Jackson’s final two years at McKinney, as father Bryan reflected, were largely spent toting the rock on power runs.

But the world will be surprised, as dad Bryan said, to see what Jackson can do in space. Riley had been recruiting him since his sophomore year at McKinney, when Jackson played under a different offensive coordinator that more heavily emphasized his speed. He was a “complete back,” as Jackson’s former McKinney High head coach Marcus Shavers said, able to run routes and catch passes “better than anybody in the program.”

“I’m trying to build that into my game, trying to get a little more of the elusiveness into my game — like, I’ve been working on it,” Jackson said last week.

He’s had an ideal mentor in Marks, his roommate on the road throughout 2024, as Jackson’s father said. He’d watched Marks arrive early and stay late. He’d watched Marks study film. He’d watched Marks rehab his body. When Marks went down early in USC’s regular-season-ending loss to Notre Dame, Jackson stepped up, running for 71 yards on six carries; he and redshirt freshman A’Marion Peterson, a 220-pound force himself, are set to assume the torch from Marks and Joyner as USC’s primary backs come tonight in Las Vegas.

And both have a chance against Texas A&M to jockey for a prime role in 2025, even as the Trojans added quick-twitch RB Eli Sanders in the transfer portal. Three Texas A&M starters on the defensive line — Nic Scourton, Shemar Stewart and Shemar Turner — are set to opt out in preparation for the NFL draft, giving USC a window to show strength at the line of scrimmage.

“It’s a tremendous opportunity for those two,” Riley said of Jackson and Peterson at a Las Vegas Bowl press conference Thursday, “to show that they can do the things that great backs in our offense have to do, and you’ve got to be able to do all phases well. It’s not just the power that you run with ... obviously, knowing you have to be great in pass protection, you have to be great receivers, you have to do it all.”

“They’re going to get a great chance,” Riley continued, “to show why they should be the guy here.”

It was a chance that Jackson last week called “one of the biggest of my life,” a freshman mature enough to understand the weight of his snaps tonight.

“I’m going to go out there, give it everything I got,” Jackson said last week. “Give it all for the guys on the field in the same jerseys as me, for the coaches and for the fans.”

Offensive line shakeup

USC’s offensive front, similar to the Aggies’ defensive line, will head into the Vegas Bowl with some changes.

Center Jonah Monheim is headed for the NFL draft, and right tackle Mason Murphy has entered the transfer portal.

In their place, backup and former walk-on Kilian O’Connor, from Santa Margarita High, and redshirt freshman Tobias Raymond, from Ventura High, will start against A&M, Riley confirmed Thursday. It’ll be a test of USC’s offensive-line cohesiveness under newly tabbed OL coach Zach Hanson, as O’Connor and Raymond have a combined 179 snaps of collegiate football between them.