USC coach Lincoln Riley knows what defensive struggles can cost a team. The Trojans had an excellent 11-win season in 2022, but they gave up more than 1,000 combined yards in two losses against Utah and allowed 46 points in a Cotton Bowl loss to Tulane. While Riley retained defensive coordinator Alex Grinch, he understood that improvements had to be made. 

Speaking at Pac-12 Media Day on Friday, Riley highlighted one specific area in which he expects to see his team progress: The defensive front. 

"It was fun to see, again, the competitive depth, especially in some key areas -- the defensive front seven chief among those," Riley said. "I think watching this team unfold from spring, into summer, a lot to be excited about." 

It is clear that USC has to get better near the trenches. The Trojans had a below-average run defense last season -- finishing seventh in the Pac-12 by allowing 148.6 yards per game -- and their two leading sack artists are gone. That includes Tuli Tuipulotu, who led the entire nation with 13.5 sacks. 

Riley's emphasis on the defensive front seven is evidenced by the work he did in the transfer portal. Of the robust class of 15 transfers the Trojans brought in for the 2023 cycle, seven play near the defensive line of scrimmage. 

"I think the obvious potential impact on our defense and attacking the areas that we need to with proven players that have done it at a high level was very, very important," Riley said. "All those guys were just a great fit. They made sense from day one and they've been great within our locker room and our team up to this point." 

USC was able to pull in a trio of four-star defensive line transfers in Bear Alexander (Georgia), Anthony Lucas (Texas A&M) and Jack Sullivan (Purdue). Alexander and Lucas are former blue-chip prospects with a lot of football left, while Sullivan is a proven veteran that had nine sacks in five seasons with the Boilermakers. 

Four-star linebacker Mason Cobb was an All-Big 12 selection while starring at Oklahoma State in 2022. He has made such an early impression on Riley that he was one of two player representatives, alongside reigning Heisman Trophy winner Caleb Williams, chosen to represent the Trojans at Pac-12 Media Day. 

Mix USC's big additions in with returning stars like Shane Lee and Eric Gentry -- one of the Pac-12's top linebacker duos -- and it is not hard to see the Trojans taking big strides along the defensive front. It could be what they need to finally breakthrough to the College Football Playoff.