Overview
- Manager Craig Counsell said Tuesday the 24-year-old right-hander will have season-ending elbow surgery after leaving Friday’s start with forearm pain.
- Reporting from multiple outlets points to a torn ulnar collateral ligament in his elbow, and surgeons will decide during the operation whether it is full Tommy John or a less invasive repair.
- Horton exited after 17 pitches against Cleveland and was placed on the 15-day injured list, with a move to the 60-day IL expected when the Cubs need a roster spot.
- The rotation was already thin with Matthew Boyd on the injured list, and Chicago is counting on Justin Steele’s pending return plus depth options such as Javier Assad to cover innings.
- Horton finished runner-up for 2025 NL Rookie of the Year with a 2.67 ERA and opened 2026 with a 2.45 ERA over 7⅓ innings, while a typical Tommy John recovery often runs 14 months or more.