The Guardians signed Kelly to a minor-league contract with an invitation to spring training Monday.
Kelly logged one scoreless relief outing in his major-league debut for the Cubs this season. He spent most of the year at the Triple-A level, collecting a 4.62 ERA and 58:41 K:BB across 50.2 innings of work. Kelly will compete for a roster spot in spring training but will most likely wind up at Triple-A Columbus, where he'll provide lefty relief depth.