That would have been the case even if Jim Knowles had stayed at Ohio State for a fourth season as the Buckeyes’ defensive coordinator. Eight of the 11 starters from Ohio State’s 2024 defense were seniors who are now preparing to play in the NFL: defensive ends Jack Sawyer and JT Tuimoloau, defensive tackles Ty Hamilton and Tyleik Williams, linebacker Cody Simon, cornerback Denzel Burke, nickelback Jordan Hancock and safety Lathan Ransom.

Even before Knowles left Ohio State for Penn State, there was talk that the Buckeyes’ defensive scheme could be adjusted in 2025. With the impending departure of the entire starting defensive line from last season, there had been subtle hints that the Buckeyes could mix up their defensive fronts more after using a four-down front almost exclusively for the past two seasons. Different alignments in the secondary were certainly possible, too, especially with the departure of the versatile Hancock, who played both cornerback and safety for the Buckeyes in 2024.

More drastic defensive changes could be on the table now that Ohio State has hired Matt Patricia as its new defensive coordinator.

What exactly Ohio State’s defense will look like with Patricia at the helm is difficult to pinpoint. Patricia’s defenses with the New England Patriots, where he held his only previous full-time defensive coordinator job, were known for their variety and multiplicity, often looking different from one week to the next based on opponent matchups. Those defenses were also heavily influenced by Bill Belichick, who worked closely with the defense throughout his tenure as Patriots head coach.

Changing the scheme throughout the season would likely be a less successful strategy at the collegiate level, as coaches don’t get as much time to meet with their players and install game plans in college football as they do during the NFL season. Given Patricia’s history of using multiple fronts, though, it would come as a surprise if Ohio State’s defense relies solely on four-man fronts in 2025.

Ultimately, Patricia’s job will be to work with Ryan Day and the rest of Ohio State’s assistant coaches to build a defensive scheme that fits the team’s top defensive players, which he says has always been his philosophy as a coordinator.

“We would always morph the defense based on the talent we had,” Patricia said in a recent interview on Julian Edelman’s Games with Names podcast, referencing his time as the Patriots’ defensive coordinator. “Personnel was always the biggest thing: Who do we got? It was always us first, like, who do we have? Who are the best 11 guys we can put on the field to help us win this week, and who do they got?”

As Patricia begins his Ohio State tenure, one of his most important tasks will be determining who the Buckeyes’ best 11 defensive players are. He should already know who Ohio State’s best defender is, and everything the Buckeyes do defensively in 2025 should be built around maximizing the talents of superstar safety Caleb Downs. Ohio State often used Downs as a safety/linebacker hybrid in the middle of its defense last season, particularly in the second half of the year, and Patricia has a history of doing the same when Patrick Chung was the Patriots’ strong safety.

It’s a safe bet that Sonny Styles and Davison Igbinosun will also be starters after starting for Ohio State’s No. 1-ranked defense this past season, but whether they’ll be used the same way they were in 2024 is uncertain. Styles has the versatility to do a lot of different things for the Buckeyes’ defense, having started his career as a safety before moving to linebacker while he has a downhill skill set that could theoretically make him effective coming off the edge in certain situations. While Igbinosun has played exclusively at outside cornerback in his first two years at Ohio State, there’s a school of thought that he could be used in different ways in the secondary too, especially with Jermaine Mathews Jr., Devin Sanchez and Aaron Scott Jr. all being strong candidates to push for more playing time at cornerback.

One of the biggest personnel question marks for Ohio State’s defense is who will step up along the defensive line, which could play a big part in determining which defensive fronts the Buckeyes use primarily. 

While Ohio State eschewed the hybrid outside linebacker/defensive end Jack position that Jim Knowles initially brought to OSU over the past two years, a big reason for that was because all of Sawyer, Tuimoloau, Williams and Hamilton were best suited to play in a four-man front. This year’s projected top group of defensive linemen includes several players who could be well-suited to play in three-man fronts; Eddrick Houston, Logan George and Caden Curry would all be candidates to play the 5-technique defensive end spot, while Kayden McDonald has the body type to be a true nose tackle.

Kenyatta Jackson Jr. should see plenty of playing time as a traditional defensive end, but one of the biggest wild cards in this year’s defensive equation is C.J. Hicks, who’s expected to play primarily on the edge as a senior after being a backup linebacker for the past three years. A pass-rushing outside linebacker role has the potential to unlock his five-star talent, and whether he can establish himself as one of Ohio State’s top pass-rushers could determine how much the Buckeyes use a standup edge defender this season.

While Patricia’s defenses could include both 4-3 and 3-4 looks in the traditional sense, with Arvell Reese and Payton Pierce projecting as top candidates to play alongside Styles at linebacker, Ohio State’s primary defense will likely still feature five defensive backs in the lineup. And Ohio State will likely continue to use many of the same coverage concepts that made its pass defense the best in the country for the past two years, with Tim Walton and Matt Guerrieri both expected to have a major role in coordinating the back end of the defense with their respective promotions to co-defensive coordinator and passing game coordinator.

That said, it wouldn’t be a surprise to see a little more personnel variation in the secondary in 2025. The Buckeyes relied mostly on their starting five in 2024 except for Mathews rotating in with Burke and Igbinosun, but Hancock’s ability to play multiple positions helped enable that. While Lorenzo Styles Jr. is a potential candidate to play the dual role that Hancock did, Ohio State could also use three true safeties more often with Malik Hartford and Jaylen McClain being candidates to play big roles alongside Downs. If Sanchez proves to be what he’s expected to be as a freshman, Ohio State would also have good reason to put him on the field with Igbinosun and Mathews for three-cornerback looks, as there’s a good chance all three of them will rank among OSU’s best 11 defenders.

Neither Patricia nor anyone else at Ohio State should be looking to completely reinvent the Buckeyes’ defense after a season in which they had the best defense in the country. But adjustments were always going to be necessary for a defense that’s losing eight starters from last season who will all likely be selected in the 2025 NFL draft. How well Patricia can marry up the defensive concepts he’ll bring to Columbus with the returning talent Ohio State has on defense will determine whether Ohio State has another elite defense in 2025.