The Tigers are expected to designate Miller for assignment prior to Tuesday's game against the Rays, Evan Woodbery of MLive.com reports.
Detroit plans to call up top pitching prospect Jackson Jobe in a corresponding move, with the young right-hander set to take Miller's spot on the 40-man roster and in the big-league bullpen. Miller has made 51 appearances for Detroit this season, logging a 4.53 ERA, 0.97 WHIP and 49:13 K:BB across 55.2 innings while gathering six wins, five holds and two saves.