Michigan associate athletic director Dave Ablauf said Miller, who would have been a fifth-year senior in the fall, decided to forgo his final year of eligibility to focus on his academics. Miller said he has turned his attention to finishing his degree and pursuing business opportunities, but would "be lying if I said that the concussion thing doesn't scare me a little."
"I know I've had a few and it's nice walking away before things could've gotten worse," Miller said. "And yes, multiple schools have reached out. But I'm ready to walk away from it. My health and happiness is more important than a game."
"I know it's pretty unorthodox for a 21-year-old to see past his own nose. This game requires such a passion to excel, and my flame is burned out."
Miller started the entire 2014 season for the Wolverines and had 16 total starts in his career. He anchored a line that gave up only 26 sacks and running attack that averaged 4.6 yards per carry last season.
Michigan went 5-7 last season and fired head coach Brady Hoke. The school hired Jim Harbaugh in December.
- Molly Geary