The Giants placed Mahle on the 15-day injured list Friday, retroactive to Wednesday, due to a left hamstring strain, Justice delos Santos of The San Jose Mercury News reports.
Mahle may have tweaked his hamstring during his last start Tuesday against the Diamondbacks, when he allowed three runs on three hits and three walks while striking out three across five innings, taking his seventh loss of the season in the process. He's eligible to be reinstated from the IL in mid-June, but the Giants will have a better sense of Mahle's recovery timeline once he undergoes further tests on his hamstring. Logan Webb (knee) was reinstated from the 15-day IL in a corresponding move, but with Mahle now sidelined, the Giants may call up a starter from Triple-A Sacramento if they wish to maintain their six-man rotation.