The Philadelphia Phillies say ace Zack Wheeler was diagnosed with venous thoracic outlet syndrome and will require additional surgery that’s expected to sideline him for six to eight months. Wheeler had a follow-up evaluation following a surgery on Aug. 18 to remove a blood clot from his upper right arm. The setback jeopardizes his availability for the start of the 2026 season despite another Cy Young-caliber year in 2025.