Neftali Feliz will undergo Tommy John surgery to repair a tear in his ulnar collateral ligament.
Feliz was diagnosed with a sprained ligament in May and began a rehab assignment in Double-A in mid-July.
Feliz experienced elbow soreness after three rehab starts.
Feliz has been both a reliever and starter during his tenure with the Rangers.
The typical recovery time for Tommy John surgery is 12-15 months.
Neftali Feliz To Undergo Tommy John Surgery