 A native of Gainesville, Florida, Miller attended the University of North Carolina (UNC) at Chapel Hill, playing for the UNC Tar Heels.The Detroit Tigers selected him sixth overall in the 2006 MLB draft, and he made his MLB debut that same season after three minor league appearances.After commencing his career in MLB with a 5.70 earned run average (ERA) over 66 starts with Detroit and Florida, he converted to full-time relief in 2012 with Boston, and has since served in middle relief, setup and closer roles.