In Kimbrel, the Red Sox land one of the top closers in Major League Baseball (if not the very best). He is still only 27 years old, so he should continue to be dominant (even in his first stint in the American League). With the arrival of Kimbrel, the BoSox will move veteran right-hander Koji Uehara to a setup role.

The Padres decided to trade Kimbrel less than a year after acquiring him from the Braves in a six-player blockbuster trade in early April. Margot, Allen and Guerra are all quality prospects, while Asuaje is more of a project. Overall, this was a very strong haul for San Diego in exchange for their top reliever.

Kimbrel may not have as much value moving from spacious PETCO Park in San Diego to Fenway Park in Boston, but the opportunity to register more saves could off-set that. Margot, Allen and Guerra all have keeper-league value but are all a few years away from prominence. The biggest loser here is Uehara, who has lost his closer role in Beantown with the arrival of Kimbrel. As for San Diego, it is currently unclear who will take over the ninth-inning role.