The Mariners are looking to strengthen their bullpen this off-season, so landing Montero is a good starting point. Whether the latter emerges as the club's new closer is uncertain, though he is probably the team's top choice at present time. Seattle is reportedly looking at more bullpen options for the late innings.

The Rangers decided to move one of their top relievers in Montero, but they do have other late-inning options such as veteran Jose Leclerc and young Jonathan Hernandez. In Corniell, the Rangers get a young right-hander who has yet to pitch in the minor leagues. Therefore, he is a long-range prospect for Texas.

Montero might have some fantasy appeal if he emerges as Seattle's closer in 2021. However, he is not a lock for that job, so keep that in mind before drafting him this year. Corniell is off the fantasy radar for the time being, as he needs to show something at the minor-league level before he can become a keeper-league option.