PHILADELPHIA — Phillies pitcher Zack Wheeler underwent a thrombolysis procedure to remove a blood clot in his right upper extremity, the club announced Monday, firmly putting the remainder of his season in doubt.
While the odds of a return sometime in 2025 are long, the Phillies have yet to eliminate the possibility that Wheeler pitches again this season until more information about his condition is understood, multiple sources familiar with the situation said.
In a statement, the club said Wheeler’s course of treatment and a potential timeline to return are “to be determined.”
“We don’t know until we get further information,” manager Rob Thomson said Monday.
Until then, the Phillies must operate as if Wheeler will not return, a difficult thought for a team with championship aspirations.
Wheeler is one of the most respected figures inside the clubhouse, a true ace in an era of bullpen baseball. His potential absence creates a massive hole atop the rotation; a greater onus falls to Cristopher Sánchez, who himself is a National League Cy Young Award candidate.
The Phillies will abandon plans to move to a six-man rotation that would have padded everyone’s workloads. Instead, they will stick with a five-man unit. The bullpen, remade with Jhoan Duran at the back, must assume a larger burden. Hard-throwing lefty José Alvarado, whose expiring drug suspension makes him ineligible for the postseason, will be activated before Tuesday’s game.
Without Wheeler, every contribution matters.
“As I told everybody, ‘Just be yourselves,’” Thomson said. “That’s all we can do. Don’t try to be anybody else because they’re good enough, just the way they are.”
The rotation, considered this club’s strength, faces an inflection point. But, at the moment, those concerns are not foremost on the minds of Thomson and the rest of the Phillies.
“I mean, a lot of people are asking about the pitching staff and the team,” Thomson said. “Right now, my thoughts are just about him. This isn’t like a hamstring or a calf. This is real. This is life. My thoughts are constantly on him and his family.”
One of Wheeler’s brothers, Jacob, thanked Phillies fans in a social media post.
Shoutout to all the Phillies fans & baseball fans who’ve shown their support of my brother & family. So many messages have poured in that I’m not able to get to them all. All have been so supportive and positive. Phillies fans are truly family first and it shows. Thank you🙏
— jacob wheeler (@DigitalJacob) August 18, 2025
“Shoutout to all the Phillies fans & baseball fans who’ve shown their support of my brother & family,” he wrote. “So many messages have poured in that I’m not able to get to them all. All have been so supportive and positive. Phillies fans are truly family first and it shows. Thank you.”
Wheeler first felt heaviness near his shoulder after his start against the Washington Nationals on Friday. He was evaluated Saturday morning, when the blood clot near his right shoulder was found. The Phillies placed Wheeler on the 15-day injured list following Saturday’s game in Washington, and he returned to Philadelphia the next day with plans to undergo further evaluation at the start of the week.
The procedure took place Monday morning at Thomas Jefferson University Hospital.
Wheeler, 35, had dealt with shoulder stiffness two weeks ago that postponed his start against the Texas Rangers, but Phillies head athletic trainer Paul Buchheit said Saturday that he believes the shoulder stiffness was unrelated to the blood clot.
In retrospect, it’s incredible Wheeler was even able to pitch over the weekend. He threw a baseball at 97 mph. He allowed two runs over five innings. His ERA rose three ticks, to 2.71. He’s been one of the best pitchers in baseball since coming to the Phillies in 2020, which makes it terrifying for the Phillies to even contemplate life without Wheeler.
For now, at the very least, the clot and any potential danger were removed.
(Photo: Emilee Chinn / Getty Images)