Phoenix, AZ -- (Sports Network) - The Arizona Diamondbacks placed relief pitcher Juan Cruz on the 15-day disabled list on Sunday with a strained left oblique.

Cruz, who leads all relievers with a 10.83 strikeout-per-nine-innings ratio, aggravated the injury in the ninth inning of Saturday's contest against the San Diego Padres.

The oblique has hampered the diminutive, 145-pound reliever all season, but he is still 2-0 with a 3.23 earned run average in 37 appearances this season.

Arizona called up pitcher Connor Robertson from Triple-A Tucson to replace Cruz. The 26-year old has appeared in two games with the big club this season, allowing two hits and a run in four innings of relief.