Michigan linebacker Jake Ryan suffered a torn anterior cruciate ligament during spring practice Tuesday and is out indefinitely, the school announced.
Ryan, a junior from Westlake, Ohio, led the Wolverines in tackles with 88, including 56 solos, last season. He also had 16 tackles for loss, 4.5 sacks and four forced fumbles.
"You always hate when anyone gets injured and, unfortunately, we've dealt with our share of injuries in the last 12 months," Michigan coach Brady Hoke said. "We will support Jake to make sure he has everything he needs to get through this. I know he will attack his rehabilitation just like he does everything else and will be back when he's ready."
Ryan was named second-team All-Big Ten by the media in 2012.