The Giants reinstated Sanmartin (hip) from the 60-day injured list Wednesday.
A waiver pickup from the Reds back in November, Sanmartin ended up having his Giants debut delayed several months after suffering a significant right hip flexor strain back in spring training. The 30-year-old lefty was cleared to begin a minor-league rehab assignment in mid-May and compiled a 2.79 ERA, 0.72 WHIP and 10:1 K:BB across 9.2 innings over nine appearances between the rookie-level Arizona Complex League and Triple-A Sacramento to convince the Giants he was ready to join the big-league bullpen. He's likely to be deployed in middle relief initially.