On Saturday, depth took a bigger hit -- temporarily -- with injuries to defensive linemen Brennen Beyer and Richard Ash.
"[Beyer] strained his knee," Michigan coach Brady Hoke said. "I don't know any more than that right now, but that's what is going on."
Hoke also said Ash should be ready next week for Massachusetts, but did not specify Ash's injury.
Because of injuries and talent -- the Wolverines also lost tight end Brandon Moore this week to an MCL sprain and have reserve offensive lineman Chris Bryant out for the year with a fractured tibia -- the Wolverines have had a major youth movement.
The number of freshmen playing this season has already reached double digits.
"I want to say 12 [freshmen]," Hoke said. "It was by design and by necessity."