Pitcher Dan Straily has been called up from Class AAA Fresno, but Jonathan Singleton remains behind for one more game.
Straily was 10-9 with a 4.77 ERA in 22 starts for Fresno. He started three games for the Astros earlier in the season.
Fresno won the Pacific Coast League championship on Sunday, and will play Columbus of the International League in the AAA Championship game.