Adam underwent surgery to repair a dislocated left ankle Friday, Andy Martinez of Marquee Sports Network reports.
Recovery from the procedure will likely keep Adam out for an extended period, though the Cubs didn't specify exactly how long they expect him to be out. He's made nine appearances at the big-league level this season, struggling to an 8.22 ERA and 1.96 WHIP, but was pitching for Triple-A Iowa when he suffered the injury.