In Yamamoto, the Mets get a decent right-hander with starting experience in MLB. He is expected to compete for a spot either in the rotation or as a long reliever out of the bullpen in 2021. Polanco is a long way away from MLB, and the Mets now have Francisco Lindor as the team's long-term shortstop. So, Polanco was deemed expendable.

The Marlins recently designated Yamamoto for assignment, so did well to secure a future asset in Polanco, who turns 20 next month. Miami boasts both Jazz Chisholm and Jose Devers as shortstop prospects, so consider Polanco more of a long-shot prospect. That said, Miami did well here to get a long-range prospect in return for Yamamoto.

Neither Yamamoto nor Polanco have much in the way of fantasy value for the time being. That said, both should be on the keeper radar and Yamamoto's progress should be closely monitored during spring training.