Keuchel was Houston's sixth reliever on Thursday. He went 4 1/3 innings and yielded seven hits and four runs. Keuchel walked four, two intentionally, and struck out four. He was charged with the loss.
To make room, the Astros sent down right-handed pitchers Brad Peacock and Rhiner Cruz.
Astros manager Bo Porter said the moves give him more options in the bullpen.
"When you have Keuchel and [Travis] Blackley and [Paul] Clemens and [José] Cisnero, you have guys that you can use in a multitude of ways," Porter said. "I think it just gives us more options.
"And it also gives Rhiner an opportunity to go to Triple-A and pitch in some high stress, back-end of the game situations. We believe that in the future, he's going to be one of those guys that's going to be back in the rotation."
But with Hector Ambriz pretty much solidifying his role as the setup guy and Jose Veras, the closer, Porter said he sees it as a valuable time to get Cruz experience closing out some games.
Porter added that he anticipates a quick return.
"It's going to come and it's going to come fast because he has the stuff to do it," Porter said. "It's just looking at the dynamic of our roster and how it's shaped up and the need to have those multiple-inning guys down in the bullpen. We just saw it as the right thing to do at this time."
Glenn Sattell is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.