Michigan’s dominant defense will have to absorb a tough mid-season blow.

Jim Harbaugh announced on Monday that starting BUCK linebacker Mario Ojemudia will be out for the season with an Achilles injury. Even worse, the senior’s career is over.

Ojemudia, who started four games this year, suffered the injury in the fourth quarter of Saturday’s 28-0 win at Maryland.

According to the Detroit Free Press’ Mark Snyder, Harbaugh suggested after the game that he thought it could be season-ending.

“That is a hard, tough rehab type of injury,” Harbaugh said. “I’ve got some experience with that one. Not personally, but I’ve seen it. It’s a tough injury. Surgery and then you just can’t do anything. Can’t try to come back from that too early. But once you do rehab that, it comes back solid.

“The first time that’s happened to him. It’s the kind of injury you can come back successfully from it. But it’s also a hard and tough rehab.”

Ojemudia was starting to emerge for a Wolverines’ defense coming off consecutive shutouts for the first time in 15 years. He was third on the team in tackles (19), and second in tackles for loss (6).

His injury marks the second season-ending loss to a Wolverine defensive starter. Defensive tackle Bryan Mone broke his leg in the preseason.

Replacing Ojemudia will be another senior. Royce Jenkins-Stone will make his first start of the season on Saturday when Michigan hosts No. 13 Northwestern.