It’s not closure, and it’s not certainty, but it’s something close to both. The Phillies and their fans now know why Zack Wheeler won’t pitch for them again this year. Last week he was found to have a blood clot on the right side of his upper body.

Wheeler was diagnosed with thoracic outlet syndrome and will require additional surgery that’s expected to sideline him for six to eight months, the team announced Saturday.

The Philadelphia Phillies will not have their ace the rest of 2025. Right-hander Zack Wheeler will have surgery to treat venous thoracic outlet, the team announced Saturday. The surgery typically comes with a 6-8 month recovery, meaning Wheeler's availability for the start of 2026 could be impacted. He last appeared in a game on Aug. 15.