"He said he felt really good and threw the ball well, and he'll take the mound again tomorrow for another inning," Astros manager Brad Mills said.
Byrdak will return to Round Rock on Sunday to pitch one inning against Reno and should be activated in time for Tuesday's game against the Brewers in Milwaukee, if all goes well. Byrdak, who got a cortisone shot in his lower back a week ago, is 1-0 with a 5.23 ERA in 13 games.
Gustavo Chacin has taken over Byrdak's role as the lefty in the bullpen and has pitched well, posting a 2.08 ERA in three games. Those are his first three career relief appearances after starting 58 games in the Majors to start his career.