Rodriguez to duel Wainwright in matinee

Right-hander Dereck Rodriguez (6-4, 2.30 ERA) takes the mound for the Giants in a quick turnaround Saturday at 10:05 a.m. PT at Busch Stadium. Rodriguez has cooled off after a strong start to his rookie season, losing his last three decisions. He is 2-1 with a 2.58 ERA in seven road games. Veteran righty Adam Wainwright (2-3, 3.75) starts for the Cardinals, who are in contention for an NL Wild Card spot.