Diekman (abdomen) underwent surgery that was made necessary by ulcerative colitis on Wednesday, Evan Grant of the Dallas Morning News reports.
Although Diekman is slated to return this coming season, he'll undergo a lengthy rehabilitation process, as his colon was removed during Wednesday's procedure. The tentative plan is for him to return around the halfway point of the 2017 campaign, but a more specific timeframe should become available as his rehab progresses.