Jon Heyman of the New York Post reported on that extension possibility on Sunday, including the fact that the two sides haven't yet broached the topic. Heyman also spelled out what such a deal could cost the Red Sox, referencing the offer the superstar turned down to sign with the Detroit Tigers.

The Boston Red Sox signed Alex Bregman to a three-year, $120 million deal in the offseason. His deal has an opt-out, and an extension has become a hot topic in the last few weeks.