The Red Sox just signed Alex Bregman to a three year 120 million dollar deal with half of that deferred. The signing has created a roster crunch for the Sox.
The Red Sox already have Rafael Devers and Trevor Story on long term deals in the infield, and Triston Casas for the long term. The Red Sox have top prospect infielder Kristian Campbell major league ready as well. If the Sox think that Campbell may break camp with the team this would create a roster crunch. One of these infielders will have to move to DH or the Outfield.
For DH and Outfield the Sox have Wilyer Abreu, Masataka Yoshida, Jarren Duran, Ceddanne Rafaela, and Rob Refsnyder. Even before Campbell on the 26-man two of these players need to be in a platoon.
Masataka Yoshida in particular seems like the profile the Bucs have been acquiring. He has average at best bat speed, doesn't chase or whiff, and squares up the ball well. He also bats left handed. After the Pham signing the Bucs likely have a preference for another LHH.
Yoshida would at best be pushed to DH against RHP while remaining on the Red Sox roster. There was some tension between the Sox Management and Yoshida because he was not playing in the outfield and has a strong preference to play in the grass.