Montero has posted a 1.08 ERA, 0.96 WHIP and 19:5 K:BB across 16.2 innings in his 10 appearances with the Rangers since being promoted from Triple-A Nashville.
A once-promising starting pitching prospect in the Mets organization, Montero made the transition to the bullpen after missing the entire 2018 season following Tommy John surgery. After dominating at the minor-league level earlier this season, Montero was rewarded with a callup and hasn't seen his performance suffer while testing himself against tougher competition. Texas initially used him in lower-leverage situations, but he's started to gain traction in the middle and late innings recently, notching holds in two of his last four outings.