A team spokesman says Miller wants to focus on his studies and pursue business opportunities. Miller would have been a fifth-year senior for the Wolverines. He started all 12 games for Michigan last season.
The Wolverines have begun spring practice under new coach Jim Harbaugh, and now they'll need to replace one of their most experienced linemen. Miller redshirted in 2011 and was a backup the following year before finally starting a few games in 2013.
At the team's postseason football bust last year, Miller received the Hugh H. Rader Jr. Memorial Award as the Wolverines' top offensive lineman.