The Yankees already had a strong back-end of the bullpen with Aroldis Chapman, Dellin Betances, Chad Green, and Jonathan Holder. However, adding Zach Britton and Adam Ottavino give them the best bullpen in all of Major League Baseball. No argument needed.
Re-signing Britton provides the Yankees with a dominant late-inning lefty who can get hitters out from both sides of the plate, while Ottavino and his high-octane fastball and knee-buckling slider replaces David Robertson, who departed for the Philadelphia Phillies.
Although the Yankees have six men locked down in their bullpen already, there are still currently one-to-two vacancies remaining.