The Astros optioned Dubin to Triple-A Sugar Land on Saturday, Matt Kawahara of the Houston Chronicle reports.
Dubin fired 8.1 scoreless frames and struck out nine batters after returning to the Astros' bullpen July 30. However, he will be forced back to the minors following the return of Kaleb Ort, who returned from the paternity list Saturday. If Dubin is able to keep his hot streak alive in the minors, he figures to have a good chance of returning to Houston before the end of the year.