Lyles was placed on the injured list Monday with left hamstring tightness.
This move comes after Lyles lasted just three innings in his most recent start Saturday against the Brewers, during which he allowed three runs on five hits and four walks while striking out five. The severity of the issue is not yet known, so it remains to be seen how long Lyles will remain sidelined for. Montana DuRapau was recalled from Triple-A Indianapolis in a corresponding roster move. The Pirates have yet to announce who will replace Lyles in the rotation.