Lincoln Riley revealed Tuesday after practice that junior defensive end Anthony Lucas will miss the rest of the season with a lower-leg injury that required a procedure earlier in the day.

Lucas led all Trojans edge rushers with 231 defensive snaps played this season and 12 pressures (per PFF), though he'd yet to record a sack or tackle for loss after finishing with 3.5 TFLs and 0 sacks last season.

This was supposed to be breakout season for the former Rivals100 prospect, with renewed hype from coaches and teammates in fall camp after Lucas' quiet sophomore season, and while he's certainly looked like an improved player he won't have the chance to build on that now.

"We lost Anthony for the season. Anthony had to have a procedure done this morning on his leg so we won't have him anymore this year," Riley said. "You've got the handful of guys that we've been playing with on the edge already that are going to get opportunities and potentially more opportunities, and we'll certainly look at some of the young guys. You know, Kam Fountain, [Lorenzo] Cowan, guys like that that have been working behind the scenes and part of that development that we've been pushing so hard.

"So, I hate it for Anthony because he had really improved, he had a strong impact on our defense, but he's in a good frame of mind with it -- excited to get him back next year and get him rolling and build on all the progress he made. And in the meantime, it's going to create an opportunity for more guys to step up. It's one of those that you hate when you lose a key player, but the positive of this is there's going to be somebody else emerge that maybe wouldn't have had the same type of opportunity. So we're disappointed for Anthony, but excited about [the other guys]."

USC has struggled to get sack production from any of its edge rushers. Linebacker Eric Gentry, who has missed the last two and a half games with injury, leads the team with 2 sacks, while defensive tackle Devan Thompkins has 1.5. The Trojans have just 6 sacks overall and rank tied for 119th nationally out of 134 FBS teams in averaging just 1 sack per game.

But Lucas was at least racking up pressures and causing some disruption in the backfield even if it wasn't carrying over to the stat sheet.

Behind Lucas' 12 pressures, next among edge rushers is Shelby (7), Jamil Muhammad (6), Solomon Tuliaupupu (2) and freshman Kameryn Fountain (1).

Muhammad (188 defensive snaps) and Shelby (162) would be the likely starting duo on the edges now, with Tuliaupupu (82) likely to step into a bigger role.

Riley referenced the freshmen, but Fountain -- one of the jewel's of USC's 2024 recruiting class -- has played just 12 snaps so far and Cowan has yet to play any defensive snaps.

Riley was asked two weeks ago about Fountain's progress in practice.

“I think Kam definitely can contribute this year. I would not put that out of the question whatsoever. He’s progressing, he’s getting a lot of good reps both with our defense and with our scout-team right now, he’s getting better fast," he said.

As for the general lack of sack production, both Riley and defensive coordinator D'Anton Lynn downplayed it previously by saying it's not all about the stats. The Trojans did match a season-high with 16 QB pressures against Penn State last weekend (tying the mark they had against Utah State), after having just 6 vs. Minnesota and 4 vs. Wisconsin in previous weeks, but the production up front is hard to ignore.

It is likely why Thompkins drew his first start last week on the interior, playing a season-high 53 snaps and responding with a team-best 4 pressures.

"Sure, would you look at it and love to see some more production there? Yeah, absolutely, and we’ve had some opportunities. But the other thing is, are you affecting the quarterback? And if you look at, certainly, how well we’ve played on third downs and look at us in general, we have been able to affect teams," Riley said. "And sacks are great, and obviously we want more of ‘em, but at the same time you’ve got to be affecting the quarterback. And I do think, in large part, we are doing that. But, certainly, continuing to improve in our base four-man rushes, getting home more, hitting the quarterback more, moving him off his spots, getting sacks is something that we’ve got to continue to improve on. It’s been a big emphasis point for us.”

That becomes even more of a glaring issue with Lucas now out for the rest of the season.

“I think it’s, you rely on the development that’s been going on behind the scenes and the guys that you’ve recruited. And maybe there’s some guys that you thought, well, maybe their role won’t be quite as much this year or maybe they redshirt or whatever that, all of a sudden, they’re going to have that opportunity. And all of us can point to our careers to guys that became phenomenal, cornerstone-type players of a program that they got their first shot like this," Riley said. "And so, there’s always, anytime you lose a guy, or don’t have a guy available, sure, you’re disappointed. But then there’s always somebody that steps up.

"It’s like the mind thinks, oh, well, there’s gonna be a void there, we’re gonna go out there with 10 players. And it’s like, no, somebody else is going to step up and take advantage and they’re gonna be better because of it. So, Henny and Shaun [defensive line coaches Eric Henderson and Shaun Nua] have worked hard to develop those guys, and now they’re gonna get their chance.”

In addition to the hopes for Lucas this season, there was thought this could be a breakout season for fellow former top-100 national prospect Shelby. He and Muhammad, who led USC with 6.5 sacks last season and remains without one this year, need to step up for the Trojans, while Fountain would seem to be the best hope for a mid-season breakthrough given how he turned heads in the spring and fall camp despite being raw.