The Astros selected Madris' contract from Triple-A Sugar Land on Thursday, Chandler Rome of The Athletic reports.
Madris will take the roster spot opened up by the demotion of Cesar Salazar to Triple-A on Thursday. Madris was unimpressive during his time with the Pirates last season, slashing .177/.244/.265 with seven RBI across 123 plate appearances, but he's been solid in the minors this year. He'll most likely come off the bench while in Houston.