Montas was placed on the 15-day injured list Tuesday with right shoulder inflammation.
It was reported before the roster move that Montas recently received a cortisone shot and is hopeful to make one more start in the final week of the season. Under that best-case scenario, Montas would probably return to start one of three games in Texas during the first week of October. However, given that he last threw 3.1 innings Sept. 16, Montas may not be cleared to log enough innings to qualify for the win if he is able to make one more regular-season start. Domingo German should operate as the team's fifth starter for now.