Perez, 33, was considered a candidate to be traded in advance of the non-waiver trade deadline last month but stuck with Arizona as the club stood pat at the deadline. He now heads to Houston to provide left-handed depth in the team's bullpen, joining Tony Sipp as southpaws in the team's bullpen.
Perez has pitched to a 3.10 ERA in 48 appearances with Arizona this season while striking out 37 batters in 29 innings of work. He is a free agent after the season, and is the latest trade acquisition for an aggressive Astros' club, joining Scott Kazmir, Carlos Gomez, and Mike Fiers.
Garcia is a 19-year old lefty out of the Dominican Republic who has spent his season with Rookie-level Greeneville and Low-A Tri-City. The southpaw has posted a 0.96 ERA in 37.1 innings on the season, but did not place on MLB.com's list of Houston's top thirty prospects.