Ferrell has been shut down with shoulder impingement, reports The Detroit News.
The tendons and bursa are inflamed and the swelling is pinching parts of the rotator cuff. Ferrell said he pitched through the pain most of last year and during the Arizona Fall League, so at this point, it seems to be chronic. Detroit's pitching coach is working with him on a mechanical change to shorten what is characterized as an "exaggerated" backswing. But there is no timetable for Ferrell to resume his throwing program.