Just like the transfer portal, the college football coaching carousel never slows down. That leads to plenty of changes that will make big impacts for a number of teams year over year.
Yesterday, I broke down the six biggest offensive coordinator upgrades and downgrades for college football in 2025. Today, we're going to take a look at the coordinators on the other side of the ball.
With that said, let's dive into the biggest college football defensive coordinator upgrades and downgrades for 2025.
Biggest College Football Defensive Coordinator Upgrades
Clemson Tigers
Wes Goodwin ➝ Tom Allen
Say what you want about Dabo Swinney, but he’s loyal. He prefers to promote from within, and he doesn’t put his play-callers on short leashes.
Sometimes that produces tremendous results and the kind of chemistry that can only be born out of familiarity. But when that preference for continuity goes south, things grow stale quickly.
Goodwin’s defenses didn’t live up to the talent he was working with, full stop. In 2024, four Tiger defenders made All-ACC teams, yet they barely cracked the top 50 in scoring defense (23.4 PPG, 49th).
The reason for the Tigers’ poor scoring average was their penchant for allowing explosive plays. They finished inside the top 10 in terms of Havoc but surrendered 28 plays from scrimmage of 30 yards or more (91st).
Toss in a lackluster red-zone defense, and it was clear they needed a change by season’s end.
Tom Allen arrives from Penn State after a successful stint as the Nittany Lions’ defensive coordinator. He was named a Broyles Award semifinalist and helped PSU achieve top-10 rankings in scoring and total defense, sacks, takeaways and Havoc.
And unlike Goodwin, he wasn’t gambling to create negative plays only to surrender big chunk plays as a result.
Given the defensive line talent, Allen can stick to the same recipe this fall for the Tigers, and I’m expecting a top-10 defense that powers Clemson on a deep run in the College Football Playoff.
Florida State Seminoles
Adam Fuller ➝ Tony White
Teams gouged Florida State for big plays last year, and Fuller was powerless to do anything about it. He couldn’t create an ounce of Havoc (103rd), get off the field on third downs (111th) or generate any turnovers (six, 132nd).
The team quit on him during a three-game stretch against UNC, Miami and Notre Dame in which they surrendered 123 points. You can’t come back from a season like that as a coordinator, and Mike Norvell made the right choice to move on.
In comes Tony White, one of the best defensive minds the sport has to offer.
For starters, he’s a chameleon when it comes to scheme; there may not be a more multiple defense in the ACC this season than White’s. His base is a 3-3-5 look, but he will deviate from that at times, walking a linebacker down, making it an even or four-man front.
Last year at Nebraska, his defense succeeded without creating a ton of negative plays or takeaways. What his team did do was get off the field on third down (31st) and bow its neck in the red zone (20th).
The Cornhuskers dominated Colorado and replicated that success seven weeks later in a near-upset of Ohio State. This goes to show how White can take away a strength. He rattled Sanders with different coverages and pressures en route to the second-lowest QBR of his career (21.3).
And when it came to the Buckeyes, he stuffed their running game for four quarters (2.1 YPC, 64 rushing yards).
The Xs and Os upgrade here is massive and should have the 'Noles back in the defensive middle class of the ACC in no time.
North Texas Mean Green
Matt Caponi ➝ Skyler Cassity
The Mean Green defense was a doormat under Caponi. I could list all of their deficiencies, but you don’t have all day to scroll.
Suffice it to say, this team was never going to punch through to the top of the American without a complete overhaul of its defense, starting with the one calling the shots.
Enter Skyler Cassity.
The wunderkind was the youngest defensive coordinator at the FBS level last season when he coached at Sam Houston. His lack of experience didn’t hold him back.
The Sam Houston defense was elite, playing so far above its talent level that I’m a bit surprised a Power Four program didn’t take a run at Cassity.
The Bearkats’ defense finished top-25 in key metrics like yards allowed, red-zone scoring and takeaways.
What’s interesting is that North Texas played a ton of players in its two- and three-deeps last season. So, despite returning just three full-time starters, it actually ranks 30th in returning defensive production.
That gives Cassity some useful experience to work with right away.
The three most talented defenses the Mean Green are set to face in 2025 — Washington State, USF and UTSA — all come to DATCU Stadium in Denton.
If Cassity can work even 80% of the magic he did with Sam Houston last season, UNT will be in the running to win the American late into November.
Miami Hurricanes
Lance Guidry ➝ Corey Hetherman
Miami wasted a generational talent at quarterback last season. Cam Ward broke nearly every Hurricane passing record while reaching 158 career passing touchdowns, a D-I record when combining his FCS and FBS stats.
How did the Miami defense repay his mastery from the pocket? By peeing down its leg down the stretch.
After a 9-0 start, the Hurricanes closed 1-3, and they can hang those losses on their defense.
Georgia Tech controlled the game in an upset of Miami by rushing for 271 yards. Syracuse flipped the run/pass ratio by throwing for 380 yards in an upset that pushed the Canes out of the ACC Championship and the College Football Playoff in one fell swoop.
And just to add insult to injury, the defense gave up 42 points in the Pop Tarts Bowl to Iowa State in yet another humbling defeat.
Three days later, they canned Lance Guidry.
Corey Hetherman won the AFCA Assistant Coach of the Year award as the defensive coordinator at James Madison back in 2021. Then he did a fantastic job with the Minnesota defense last fall, ranking inside the top 10 in scoring and total defense.
His defenses are built on aggressiveness, which translates to negative plays. But it all starts with defending the run, something Miami needs to clean up after wilting late in the season.
When you can scheme your way to national awards and top-10 rankings at stops like JMU and Minnesota, Miami’s locker room must feel NFL-esque. Five four-star recruits portaled in on defense, with four of them joining a new-look secondary.
I expect the tackling and Havoc to achieve a noticeable uptick in Hetherman’s first year on South Beach.
Biggest College Football Defensive Coordinator Downgrades
Notre Dame Fighting Irish
Al Golden ➝ Chris Ash
Notre Dame’s defense was simply fantastic last year. And it’s a testament to Golden that despite losing Ben Morrison midseason to a hip injury, the defense didn’t skip a beat.
His ball-hawking defense led the nation in takeaways with 33. The secondary, in particular, was so disruptive, and there’s really nowhere to go but down this fall.
But Golden would have found a way to keep the good times rolling. Chris Ash, meanwhile? I’m not sure he has it in him.
The former Rutgers head coach has been on staff at a number of big-time programs. He was the DC or co-DC at Wisconsin, Ohio State and Texas. But the problem with Ash’s résumé is that he’s gotten worse at each stop.
At Wisconsin, his pass defenses were elite. But he job-hopped to Arkansas, and in 2013, he was humbled. His defense gave up 37 points per game during a nine-game losing streak to end the season.
He served as a co-DC at Ohio State the next two seasons, but Luke Fickell ran that defense.
Then, in 2020, he got his opportunity to call plays again at Texas. His defense was mediocre at best, finishing 61st in scoring, 64th in total defense and 83rd in plays of 20-plus yards allowed.
Since then, he’s bounced around the NFL as a position coach.
This is a massive downgrade. I’m shocked, given how important the Notre Dame defense is to the program’s overall success, that they went with a journeyman coach trending in the wrong direction.
