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.