John Baker started Friday at catcher in place of Nick Hundley. Black listed Hundley's trouble against lefties (.108 season average) and fatigue as reasons.
"Nick caught three of the four games [in Houston] and I want to give him a day away from starting," Black said. "And Baker's had some good at-bats lately. You gotta use your whole roster."
Baker is hitting .321 (9-for-28) in his past 10 games prior to Friday.
With his go-ahead grand slam on Thursday against Houston, Alexi Amarista became the fifth Padre in team history to hit a grand slam for his first Major League homer and the first since 2002 (Ramon Vazquez).
Third baseman Chase Headley entered Friday's game with a .329 batting average (25-for-76) in his last 20 games. Headley leads the Padres in hits and RBIs.
The Padres were 3-3 against the Rockies this season entering Friday, with a 1-2 record at Coors Field. Sixteen games back in the National League West, the Padres trail Colorado by just two games.