Montero dropped to 3-5 on the season after striking out two batters and allowing two runs (one earned) on two hits across 1.1 innings out out the bullpen in Tuesday's 4-2 loss to the Astros.
Montero had made all 13 of his previous appearances this season as a starter, but with Tarik Skubal returning from the injured list last weekend and both Casey Mize (adductor) and Justin Verlander (hip) on track to be activated Wednesday and Sunday, respectively, the Tigers no longer have room in the rotation for Montero for the time being. According to Evan Petzold of The Detroit Free Press, Tigers manager A.J. Hinch said prior to Tuesday's contest that Montero will remain in the bullpen for at least the next two series, though it's possible Detroit could expand its rotation to six to include the young right-hander when the club begins a stretch of 11 games is many days June 22. Despite a general lack of strikeouts, Montero has been effective as a starter this season with a 3.61 ERA and 1.01 WHIP over 72.1 innings.