There is a real chance the Colorado defense has 11 new starters when it takes the field Sept. 3 at Georgia Tech.

It would make sense, too. The Buffaloes ranked at or near the bottom of the Big 12 in most statistical defensive categories during 2025’s 3-9 campaign. Defensive coordinator Robert Livingston returned to the NFL, taking a high-ranking position on Vance Joseph’s staff with the Broncos and being replaced by Chris Marve. There are new position coaches at all three levels of the defense and most of the key contributors either graduated or transferred.

If there are any holdovers from last season’s starting lineup, it will be in the secondary as cornerbacks RJ Johnson and Makari Vickers, as well as veteran safety Ben Finneseth, are the three returners on the entire defense who played regular snaps at times last fall.

Like just about every other position group, however, the secondary’s success will be defined by the impact the newcomers make.

Let’s meet the entire unit:

The cornerbacks

Coming out of spring practices, Deion Sanders was ready to name the top cornerback on the roster and it was a surprise: Cree Thomas.

The redshirt freshman who played in just three games last season at Notre Dame made plays all throughout the spring and appears to have solidified himself as a starter, as well as a leader evidenced by his appearance at Big 12 media days, heading into his first season at CU. The talented player from the Phoenix area came to the Buffs looking to play right away knowing his path to seeing the field at Notre Dame was likely blocked by several other young players at his position.

The starter opposite Thomas is anyone’s guess. Johnson, who enters year three with the Buffs, should get plenty of looks in fall camp. So should James Madison transfer Justin Eaglin, who played four seasons with the Dukes and helped the program reach the College Football Playoff for the first time last fall. Eaglin had an interception in the first-round loss at Oregon.

Another veteran from the Sun Belt, Emory Floyd is also a name to watch next month as like Eaglin, he also received all-conference honors in 2025 after playing a big role at Appalachian State. He and Vickers, a former Oklahoma transfer who impressed at times for a struggling CU defense last season, should round out a likely group of five players competing for two spots.

The safeties

CU has a knack for finding productive safeties out of the portal and they almost all end up wearing No. 7. First, it was Cam’Ron Silmon-Craig, who came with Coach Prime from Jackson State in 2023 and is now in the NFL. Last season, Tawfiq Byard was the best player on the defense and wound up transferring to Texas A&M for big NIL money.

Now, the Buffs are hoping Vanderbilt transfer Randon Fontenette can make a similar impact in the No. 7 at one of the starting safety spots. Fontenette made 24 starts across two seasons with the Commodores and adjusted quickly to a new defense this spring.

The other safety spot might be secured already, too, as New Mexico State transfer Naeten Mitchell was another spring standout and has become a leader in the locker room, representing the team at Big 12 media days. He had a breakout 2025, leading his team with 93 tackles to go with six pass breakups and four forced fumbles, earning second team All-Conference USA honors.

Finneseth can’t be ignored, though, as he’s spent his entire career in Boulder. He worked his way up from a walk-on spot to playing meaningful defensive snaps for the first time last fall before a knee injury took away his final spring practice period. He’s healthy and ready to go for fall camp, though.

The nickel backs

If there’s one player who has the potential to swing the entire CU defense, it’s inside cornerback Boo Carter. 

A talented player who has a longstanding relationship with Coach Prime, Carter seemed poised for a breakout sophomore season at Tennessee last fall before disciplinary issues hindered his ability to see the field. He ultimately was dismissed from the program before the season ended.

He made the All-SEC freshman team as a return specialist, so there is a chance he could impact the game as a punt returner as well, but the Buffs will need him to be available and a productive player at the nickel cornerback spot for the defense to reach its full potential. 

Veteran Lamar transfer Paul Omodia is the other player to watch at this position.