Greg Mattison was the Michigan Wolverines’ defensive line coach from 2015-18. He had been in Ann Arbor since 2011 and was previously an assistant and defensive coordinator for the Wolverines from 1992-94 and 1995-96.

Mattison left Michigan for Ohio State this past offseason. He went from one side of the hated rivalry to the other. He is now the co-defensive coordinator for the Buckeyes.

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This change, of course, left a bad taste in some Wolverines’ mouths. Earlier this week, current Wolverine LB Khaleke Hudson talked about how Mattison — and former linebackers coach Al Washington — left Michigan for Ohio State:

“Ultimately it’s their life and I don’t hold anything against them,” Hudson told reporters on Monday. “They decided to go there. They had to make decisions for themselves and their families. I have the utmost respect from both of those guys. It’s going to be good, going to be good going up against them. I’m not really focused on that. I’m focused on the team.”

Hudson says he’s not focused on it and understands where Mattison and Washington are coming from. But before The Game, here’s what Hudson was seen wearing during warmups:

To switch from Michigan to Ohio State won’t go unnoticed. That much is known.