The Guardians selected Kelly's contract from Triple-A Columbus on Saturday, Mandy Bell of MLB.com reports.
Kelly holds a strong 1.61 ERA and 36:13 K:BB through 22.1 frames in Triple-A and pitched well in his four major-league appearances last season with the Phillies. He'll replace Hunter Gaddis in Cleveland's bullpen and likely work in low-leverage situations to begin with. Peyton Battenfield (shoulder) was moved to the 60-day IL to make room for Kelly on the 40-man roster.