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

Just as Ohio State was celebrating its national championship victory at Ohio Stadium on Sunday, news broke that Jim Knowles was heading to Penn State.

COLUMBUS, Ohio — Ohio State defensive coordinator Jim Knowles agreed to a deal to serve the same position at Penn State. The Nittany Lions hired Knowles on Monday to replace Tom Allen, who left to take the same job with Clemson after Penn State fell to Notre Dame in the College Football Playoff semifinals.

As Ryan Day looks to hire his fourth defensive coordinator in seven seasons, here are potential candidates to replace Jim Knowles.

It was the furthest thing from a happy ending between the newly minted Penn State defensive coordinator Jim Knowles and his former school.

Penn State has lured Tom Knowles away from Ohio State. The Nittany Lions have hired Knowles to serve as their defensive coordinator.

Just days after leading Ohio State's defense to a College Football Playoff national championship, Jim Knowles accepted a massive offer from Penn State. Where will Ryan Day look for his successor?

However, Knowles wasn’t in attendance. About an hour later, reports surfaced that Knowles is leaving Ohio State to serve as Penn State’s next defensive coordinator. The move leaves Day searching for a replacement. Here’s who he might consider as he enters his seventh season as the Buckeyes' head coach.

Ohio State DC Jim Knowles is expected to become the new defensive coordinator at Penn State, sources tell @YahooSports. The two sides are in the process of finalizing an agreement. Big hire for James Franklin.

Ohio State football coach Ryan Day has put together a tutorial on life after winning a national title. In the 10 days that have passed since OSU’s win vs. Notre Dame, Day has made TV appearances on The Tonight Show Starring Jimmy Fallon and The Kelly Clarkson Show.

Ohio State offensive line coach Justin Frye is interviewing for the same position with the Chicago Bears according to the Chicago Tribune.