The Athletics optioned Morris to Triple-A Las Vegas on Tuesday.
Morris gave up nine earned runs in just four innings during his MLB debut Saturday, and he'll now be sent back down to the minors in favor of Joey Estes. Morris owns a 4.45 ERA and 1.48 WHIP in 60.2 innings at Las Vegas and could rejoin the A's at some point later this summer if he gets back on track with the Aviators.