It’s not a question of whether or not he’s been a great closer. The question is, will he continue to be one for the next 5 years, and to learn the answer can cost up to $100mill.
And even if the answer is yes, how important is it for the Sox to have the closer position locked up through 2023 when the team could stand to lose so many much more important players, including Betts, Bogaerts, Bradley, and Sale, among others.
They can get another closer and probably will. Closer might not be the best use of what could be limited resources this off-season...