[1] He made his professional debut in 2017 with the Dominican Summer League Tigers, posting a 4.02 ERA across 14 games (12 starts).

[4] Montero returned in action in 2021 to play for the High–A West Michigan Whitecaps, registering a 4–8 record and 5.28 ERA with 59 strikeouts across 15 starts.

[5] Montero started 2023 with West Michigan before being promoted to the Double–A Erie SeaWolves and Triple–A Toledo Mud Hens.

[8] He was called up again to start a game on June 26, 2024, but was sent down the next day when another pitcher was activated off the injured list.

[10] On September 10, 2024, he pitched a complete game shutout against the Colorado Rockies, while facing the minimum of 27 batters.