Here's a link to reporting on Boston.com. The report says the surgery involved Story's right ulnar collateral ligament. (Yes, he's right handed.) And such UCL procedures normally require four to six months for recovery. Story had been expected to slide over from 2B to #shortstop this season to replace Xander #Bogaerts who left #Boston as a free agent. (There was already concern that Story no longer had enough arm for the position.)
https://www.boston.com/sports/boston-red-sox/2023/01/10/trevor-story-injury-elbow-surgery-red-sox/