USC Trojans’ Lincoln Riley Addresses Secondary Depth After Prophet Brown Injury

The USC Trojans suffered a significant blow to its secondary on Friday when redshirt senior cornerback Prophet Brown went down with a non-contact injury that will keep him out for the first part of the season.

Brown was in line to step into a starting role in his final season with the Trojans. He was one of three redshirt senior cornerbacks, including DeCarlos Nicholson and DJ Harvey, that have a ton of experience under their belts.

USC Trojans’ Lincoln Riley Depth Chart Big Ten Marcelles Williams Braylon Conley Injury Update Chasen Johnson DJ Harvey — Oct 21, 2023; Los Angeles, California, USA; Southern California Trojans head coach Lincoln Riley watches from the sidelines against the Utah Utes in the first half at United Airlines Field at Los Angeles Memorial Coliseum. Mandatory Credit: Kirby Lee-Imagn Images | Kirby Lee-Imagn Images

Outside of them it’s a young but incredibly talented group that is ready to make an impact in 2025. Riley expressed his confidence in the depth of the secondary.

“We feel good. The guys have done a nice job. We've got a nice rotation going on in there," Riley said. "Obviously, we've added some new pieces and some guys that bring some position flexibility to that. As always, for us, it's going to be about trying to find the best group of guys that we can put on the field, depending on what packages that we're in, but trying to find those best five DBs.”

Riley highlighted a pair of redshirt freshman cornerbacks in Braylon Conley and Marcelles Williams that have stood out during fall camp. The two former four-star recruits in the 2024 cycle each only played in one game (Utah State) last season.

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“Braylon Conley has really had a strong camp. I've been impressed with kind of his growth, and we saw flashes of that in spring,” Riley said. “So this is something we were hoping to see, but he's had a strong camp. Marcelles certainly continues to improve. Like some of the things that he's doing.”

Quarterback Jayden Maiava was asked which young cornerback has stood out he immediately mentioned Williams, before giving recognition to the rest of the group.

Williams was a four-year starter at national powerhouse St. John Bosco (Calif.). The youngest of three, Williams comes from a family of defensive backs. Their father, Maxzel, played for Nevada. Max, played safety for the Trojans and Macen, played defensive back at Arizona State. Marcelles is the latest to carry on the family business.

The local prospect has drawn lofty praise since he arrived on campus last spring. He was an immediate standout and picked off quarterback Miller Moss in the spring game a year ago. However, it did not lead to playing time last fall in a senior heavy cornerback room.

Lincoln Riley and Jayden Maiava both mentioned redshirt freshman CB Marcelles Williams as someone that has stood out during camp #USC pic.twitter.com/m8tAYz91Wd
— Kendell Hollowell (@KHollowell_) August 8, 2025

Long term, it could prove to be the most beneficial route for his development. A whole year in the program to develop physically and mentally. Work on his craft and get a better understanding of D'Anton Lynn could pay dividends.

Similar situation for Conley, who was a summer enrollee a year ago and immediately flashed potential, but it was understood that is time would come in the future.

Lincoln Riley says redshirt freshman CB Braylon Conley has had a strong fall camp pic.twitter.com/GngDC98XGG
— Kendell Hollowell (@KHollowell_) August 8, 2025

Well, the future is now the present. Both players are competing to be a part of the two-deep depth chart. UCF transfer Chasen Johnson started four games as a true freshman last season under cornerbacks coach Trovon Reed and vying for a spot with Southern Cal.

Freshman Class

The name to keep an eye for in the fall at the nickel position is four-star freshman Alex Graham. The Detroit native was a late add to the 2025 class, after flipping his commitment from Colorado to USC on the first day of the early signing period.

Graham was a standout at Polynesian Bowl in Hawaii back in January, an annual All-Star game that features too high school talent. He enrolled early and took part in spring practice.

At the outside cornerback spots, USC signed two blue-chip prospects from the Inland Empire in Rancho Cucamonga (Calif.) five-star RJ Sermons and Upland (Calif.) four-star Trestin Castro.

Freshman cornerbacks RJ Sermons (42) and Trestin Castro (37) going through Cover 2 drills #USC pic.twitter.com/SFDybXvvUQ
— Kendell Hollowell (@KHollowell_) July 30, 2025

Sermons was originally the No. 1 ranked cornerback in the 2026 class but decided to reclassify to the 2025 class in May. On tape, Sermons is a technician, and it shows up in person. He was one of the fastest players in California this past spring, having reached the state finals in the 200m.

Castro is long and athletic. He has a receiver background, which helped turn him into a ball hawk in high school. The Southern California native took part in spring ball.

Even if Sermons and Castro don’t earn significant playing time on defense, expect them to contribute on special teams.

Freshman Class

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