After 21 years with the program, linebackers coach and co-defensive coordinator Luke Fickell moved on Saturday morning, when he accepted the head coaching position at Cincinnati. It was a long time coming for Fickell; a head coaching job is something he probably deserved at this point in his career.

Fickell's departure obviously leaves a massive hole on Ohio State's defense.

The good news is Urban Meyer will have no shortage of options for these positions. Let's examine some potential candidates to replace Fickell.

Potential Replacements for Luke Fickell

Charlie Strong — Former Texas head coach

We might as well get this one out of the way first.

This is a stretch as Strong spent his last six seasons as a head coach, and if he takes another job this year it's probably not going to be a coordinator position. And if reports are true, he could soon be South Florida's next head coach.

But Strong and Meyer worked together at Florida — he was Meyer's defensive coordinator and linebackers coach with the Gators — so who knows?

Strong and Meyer's relationship today is different than it was back when they worked together, so that's another thing factor in all of this. But if those differences have been pushed aside, maybe Strong comes to join Ohio State for a year or two as a coordinator before getting another head coaching position?

Justin Wilcox — Wisconsin defensive coordinator

After being let go by USC at the end of the 2015 season, Wilcox found a new home in Madison this year and turned the Badgers into one of the best defenses in the country. It's always tough to move within the same conference, but if Meyer thinks highly enough of Wilcox — who also has stops at Boise State, Washington and Tennseee — maybe he goes hard after him.

Marcus Freeman — Purdue co-defensive coordinator/linebackers coach

The former Ohio State linebacker has coached for the Boilermakers the last three seasons leading the same position he played in college. A look at Freeman probably wouldn't come with the "coordinator" title as Meyer would likely only consider him to be a position coach. That'd mean Greg Schiano is likely to stay on staff for at least one more year and he'd be the full-time defensive coordinator.

Note : Freeman will not be on Urban Meyer's staff. Luke Fickell announced he will join his own staff at Cincinnati.

Rob Harley — Pittsburgh linebackers coach

Another one that probably falls under the position of being a position coach and not a coordinator is Harley, the current linebackers coach at Pittsburgh. Harley played safety at Ohio State from 2001-05 so the ties are obvious. He has previous coaching stops at Ohio Dominican, Michigan State and Florida International prior to Pittsburgh.

Billy Davis — Ohio State quality control staff

This would be somewhat out of left field, but Davis is currently a quality control member on Ohio State's staff who has a ton of previous coaching experience in the NFL. Davis and Meyer are good friends dating back to the mid-1980s when they were teammates at Cincinnati.