Stewart was recalled from Triple-A Oklahoma City on Sunday.
Stewart's promotion this time around comes under unfortunate circumstances, as he'll join the roster as the corresponding move to the placement of ace Clayton Kershaw (biceps) on the DL. Stewart owns a 2.41 ERA through four starts in the Pacific Coast League, and should be able to provide the team with a long-relief option as it sorts out the long-term rotation plan, which depends heavily on the status of Kershaw.