Lively will undergo season-ending surgery to reconstruct his right elbow UCL and repair his flexor tendon.
Lively and the Guardians made the decision to undergo the operation after receiving a second opinion from Dr. Keith Meister in Texas earlier this week. The surgery is likely to sideline him at least 12-to-16 months, but more details on a timetable should be available after the procedure. Lively, 33, is set to reach arbitration eligibility for the first time this offseason.