Here are three potential options who could fill the Ohio State Buckeyes' defensive coordinator vacancy in 2025.

Why is Jim Knowles a great fit to lead Penn State's defense? Get to know the former Ohio State assistant coach

The departure of defensive coordinator Jim Knowles adds a challenge for Ohio State, which was already dealing with heavy roster turnover on defense.

Ryan Day is once again dealing with the consequences of success in college football after leading Ohio State to a national championship.

COLUMBUS, Ohio — Ohio State athletics director Ross Bjork stood behind Ryan Day when many wanted the football coach removed. Now, after Day led the Buckeyes to a College Football Playoff National Championship, Bjork is maintaining his trust.

Ryan Day and the Ohio State Buckeyes celebrated their 34-23 national championship win against Notre Dame on Sunday at Ohio Stadium. While giving his speech, Day shouted out an assistant coach after a remarkable season. Day praised safeties coach Matt Guerrieri, calling the assistant one of the "brightest minds" in college football.

Let's take a look back at Sports Illustrated's best images and coverage from the Buckeyes' championship night.

The early betting favorite to win next year’s national championship is Ohio State. The question nobody can really answer at this time is what sort of game will the Buckeyes or anyone else return to when they kick it off again seven months from now.

The Buckeyes beat the Fighting Irish 34-23 to win the inaugural 12-team College Football Playoff, their first national championship since the 2014 season

Jesse Temple: Ohio State has been a juggernaut during a three-game winning streak in the Playoff, embarrassing Tennessee and Oregon. Notre Dame has won 13 straight games and put together a fantastic season. But Ohio State’s balance and overall talent should emerge. … Ohio State 24, Notre Dame 14.

Ohio State quarterback Will Howard became the first quarterback to throw for 1,000 yards in the College Football Playoff after a strong first half against Notre Dame. By hitting the mark, Howard set the record for most passing yards in a CFP run.