Carpenter is making his first MLB appearance since May 31, when he tossed four innings against the Angels but suffered an oblique injury that sidelined him until mid-July. He's is 2-8 with a 5.30 ERA in 13 starts with Triple-A Toledo this season.
Stewart, the No. 4 pick in the 2013 Draft, will make his second career start after allowing three runs over 4 1/3 innings in a loss to the Tigers on Sunday. Stewart struck out one and gave up eight hits.