The Tigers announced the move Friday. Detroit also activated outfielder Leonys Martin from the DL, optioned outfielder Mikie Mahtook to Triple-A Toledo and recalled right-hander Victor Alcantara from Toledo.
Fulmer was initially set to start Sunday against Boston. The 2016 American League Rookie of the Year, Fulmer appeared to be Detroit's ace entering this season, but he's gone just 3-9 with a 4.50 ERA for the rebuilding Tigers.
Martin is hitting .257 with nine home runs and 29 RBIs. He's been out with a left hamstring strain.
Martin was in the starting lineup Friday night in center field. He hasn't played since July 1.