The Athletics optioned Morris to Triple-A Las Vegas on Monday.
Morris has appeared in two games out of the Athletics bullpen since being called up from the minors June 29, allowing four runs on 10 hits and three walks while striking out two across six innings. He'll head back down to Triple-A, where he has turned in a 4.41 ERA, 1.39 WHIP and 60:29 K:BB over 79.2 innings while working out of the rotation.