Kremer was returned to Triple-A Norfolk following Saturday's doubleheader against the Blue Jays, Roch Kubatko of MASNSports.com reports.
Kremer was called up as the 29th man to serve as the starter in Saturday's matinee against Toronto, and he allowed five runs on seven hits and a walk while striking out two in four innings. The 25-year-old has a 5.40 ERA in 53.1 innings in Norfolk.