In year two under Deion Sanders, Colorado established a clear defensive identity: getting after the quarterback.

While there are plenty of starters for Robert Livingston to replace heading into his second year as the Buffaloes’ defensive coordinator, he’s got about as much returning production up front as he could ask for.

CU’s defensive improvement from year one to year two was somewhat remarkable and if that group wants to take another step forward in 2025, it’ll have to do it without Heisman Trophy winner Travis Hunter locking things down in the secondary.

The best place to start, though, is with a good chunk returning from a defensive line that led the Big 12 in sacks last season.

Despite losing veterans like B.J. Green, Chidozie Nwankwo and Shane Cokes to graduation and a promising young edge rusher in Taje McCoy to the transfer portal, the Buffs still return three starters and a few other key contributors from last year’s group up front that is now led by the trio of Warren Sapp (pass rush coordinator), Domata Peko (defensive line coach) and George Helow (defensive ends coach).

Here are all the names you need to know:

On the edge

Cherry Creek’s own Arden Walker is quickly becoming one of the faces of the 2025 Buffs.

With the likes of Hunter, Shedeur and Shilo Sanders, Cam’Ron Silmon-Craig and others off to the NFL, there’s no one better to step into the spotlight than a local kid whose dad (Arthur) also starred for the Buffs in the late 1980s. Walker, who played the first two years of his career at Missouri, had the best season of his college career last fall, ranking second on the team with 4.5 sacks and playing a massive role in the run game.

He’ll likely be joined among the starters by Samuel Okunlola, a former Pittsburgh transfer who shined in his first season at CU. Like Walker, Okunlola had his flashes as a pass rusher while also being a force against the run.

Behind that duo, the likes of Keaten Wade and Quency Wiggins will likely be thrust into bigger roles. Wade was arguably the breakout star on defense in the second half of the season, quickly becoming a key piece to the defensive end rotation after a standout performance at Arizona. He had a tackle for loss in each of the final four games of the season.

Wiggins is still trying to put it all together after arriving in Boulder as an LSU transfer and a former five-star recruit out of Louisiana. He might be the most physically imposing player on the entire Buffs roster at 6-foot-5 and 255 pounds. He remains a potential breakout star in 2025.

On the interior

Alongside Walker and Okunlola, interior lineman Amari McNeill is the other returning starter up front. He has continued to show signs of improvement across his two seasons at CU and was one of the team’s four best defensive linemen by the end of last season, racking up 25 tackles (six for loss) and 3.5 sacks.

McNeill projects to be joined in the interior starting duo by Alabama transfer Jeheim Oatis, the Buffs’ big name transfer addition defensively during the offseason. Oatis played in 29 games with 13 starts across three seasons with the Crimson Tide, accumulating 52 tackles (3.5 for loss) and 1.5 sacks. He was on campus in time for spring practices and seemed to quickly become a favorite of Sapp and Peko, the duo primarily coaching the interior defensive linemen.

Behind McNeill and Oatis are a handful of players who all have the potential to become key pieces of the rotation inside. Tawfiq Thomas and Anquin Barnes Jr. both came on strong near the end of last season, while Taurean Carter projected to play heavy snaps before suffering a season-ending injury just two games into the season.

There’s also two more newcomers in Texas State transfer Tavian Coleman and Fresno State transfer Gavriel Lightfoot, both multi-year starters in Group of Five conferences hoping their production translates to the Big 12.

The freshmen

Aside from the obvious future NFL talents, there might not be a harder position group to earn playing time as a freshman than on the defensive line. But the Buffs have a few that wouldn’t be surprising to see take the field at some point this fall.

Alexander McPherson and London Merritt both arrived this spring as four-star recruits from IMG Academy and had teammates and coaches raving about their size and skill sets. You could also include redshirt freshman Brandon Davis-Swain in that group as the Detroit native and fellow former four-star recruit looked the part this spring as a player capable of playing a much bigger role in his second year at CU.