The 22-year-old Grichuk hit his team-leading 10th home run Thursday night and is batting .315 with 32 RBIs. He's among the PCL leaders in slugging percentage and is batting .451 against left-handers.
The Cardinals acquired Grichuk, a first-round pick by the Angels in 2009, from that team in the offseason. He was 3 for 21 in an earlier stint with St. Louis, making four starts.
The 29-year-old Robinson appeared in 23 games and was batting .152 with two RBIs.