Penn State announced Monday it had hired Jim Knowles as its defensive coordinator. According to multiple reports, Knowles reached a three-year contract with an average annual salary of $3.1 million. Knowles is a Philadelphia native. In a statement, Knowles said he was "excited for this opportunity" to join the Nittany Lions' program.

After Michigan football ran, ran again, and ran some more against rival Ohio State in 2021, Ryan Day recognized that he needed to make something of a drastic change. Out was longtime OSU staffer Kerry Coombs as the defensive coordinator, and in was Oklahoma State DC Jim Knowles.

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