Muller (hand) started Saturday for Triple-A Gwinnett, covering 4.2 innings and striking out five while allowing five earned runs on six hits and one walk.
Muller was back on the mound for Gwinnett for the first time since July 14 after he demonstrated enough progress in his recovery from a fractured right hand to return to action. The left-hander was fortunate to avoid an extended absence since the injury wasn't to his pitching hand, but the injury along with Atlanta's trade-deadline acquisition of Jake Odorizzi may have closed Muller's window for joining the big club in any case. Atlanta demoted struggling No. 5 starter Ian Anderson to Triple-a Gwinnett on Sunday, but Odorizzi is replacing him as a full-time member of the rotation.