Sanmartin will be called up from Triple-A Louisville to start Monday against the Pirates, Charlie Goldsmith of The Cincinnati Enquirer reports.
Sanmartin was acquired along with Sonny Gray from the Mariners back in 2019, and he's slated to make his big-league debut Monday. The 25-year-old has spent most of this season at Triple-A and posted a 3.94 ERA, 1.25 WHIP and 89:23 K:BB over 82.1 innings. He's filling the rotation spot of Wade Miley (neck) and could make another start next weekend if Miley is unable to return from the injured list.