The Astros selected Leon's contract from Triple-A Sugar Land on Tuesday, Matt Kawahara of the Houston Chronicle reports.
The 26-year-old is taking the roster spot of Joey Loperfido, who was traded to the Blue Jays as part of the package for lefty starter Yusei Kikuchi. Leon has a .297/.377/.519 slash line with 19 homers and 23 steals in 93 games at Triple-A this season, and he could see regular playing time in right field until Kyle Tucker (shin) is ready to return from the injured list.