Chapman underwent successful left thumb surgery in Los Angeles on Thursday. The club failed to disclose a specific timetable but he's expected to be healthy prior to spring training, Jane Lee of MLB.com reports.
Specifically, Dr. Steven Shin performed an ulnar sided sesamoid bone excision along the left thumb. It's unclear when Chapman suffered the left thumb injury -- though he dealt with various right hand/wrist injuries during the year -- especially since his production remained at a high level throughout the final few weeks of the 2018 season. He finished off the year with a slash line of .278/.356/.508 with 24 home runs and 68 RBI in 145 games.