PHILADELPHIA — Philadelphia Phillies ace Zack Wheeler's season is over.
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.
Wheeler had a follow-up evaluation following a procedure Monday to remove a blood clot from his upper right arm. After receiving a second opinion, it was recommended that Wheeler undergo thoracic outlet decompression surgery in the coming weeks. Such a surgery would threaten Wheeler's ability to start the 2026 season on time.
"It's disappointing, but everybody knows it's out of our control," Phillies manager Rob Thomson said. "We're happy he's going to be healthy, because it's a very serious thing that he went through."
Thoracic outlet syndrome is a condition in which bones or muscle press on blood vessels in the upper chest, near the shoulder, causing pain or numbness. Repetitive arm movements are a common cause, making baseball players and swimmers more susceptible, according to the Cleveland Clinic.
Decompression surgery involves removing bone or tissue that's causing the constriction.
Wheeler had been experiencing some shoulder soreness for several starts, but after saying he felt "normal" following his last start in Washington on Aug. 15, he later started feeling "heaviness" in his shoulder. The Phillies trainers decided to get him evaluated because it was a different symptom for him.
They had Wheeler examined by Nationals team doctors, who discovered the blood clot. The Phillies believe the clot was an acute onset, not related to the previous shoulder soreness.
"He wasn't exhibiting any of the symptoms that ultimately drove us to get the Washington Nationals docs involved. They were great. They expedited everything," said Paul Buchheit, Philadelphia's head athletic trainer. "But we do think they were independent. Typically these things have a cluster of symptoms or symptom patterns and he wasn't exhibiting any of those until we had him evaluated."
Buchheit said Wheeler can begin his rehab throwing program approximately eight weeks after the decompression surgery. What that process will look like is unknown at the moment, and it's not front of mind for the Phillies' front office yet.
"I'm glad he's OK and the prognosis is he'll be back relatively soon in the [2026] season, but it's a long time before we get to that," said Dave Dombrowski, president of baseball operations.
Wheeler, 35, was 10-5 with a 2.71 ERA in 24 starts across 149 2/3 innings this season. His 195 strikeouts lead the National League and he was widely considered a candidate in this year's Cy Young Award race. He is a two-time runner-up for the Cy Young, finishing second in 2021 and '24.
The loss of Wheeler is a blow for the Phillies, who have World Series aspirations and began the day with a 6-game lead over the New York Mets in the NL East.
"It's never good to lose a Zack Wheeler, your No. 1 pitcher," Dombrowski said. "I think we have starting pitching depth that's capable of pitching well for us. Again, you're never going to replace an individual like that. ... I've been in all different types of scenarios with pitchers being out. We have a good ballclub, and we'll be looking for other people to step up and pick up the slack for us."
The Phillies will rely on a trio of lefties — Cristopher Sánchez, Ranger Suárez and Jesús Luzardo, as well as veteran righties Aaron Nola, who missed three months with ankle and rib injuries — and Taijuan Walker to carry the rotation.
Top prospect Andrew Painter would be next up if needed, but he has struggled in Triple-A this season, his first after missing two years while recovering from Tommy John surgery.
Thomson said he hasn't noticed a dour mood in the clubhouse after the players learned Wheeler wouldn't be back. With a veteran club like the Phillies, he didn't feel the need to have a team meeting to address losing one of its most important players six weeks before the postseason.
"They're baseball players," Thomson said. "They just kind of move on. We've got a game today. They're not going to cancel it. We've got another one tomorrow. We just got to keep moving forward."
