The Philadelphia Phillies revealed Monday that Zack Wheeler underwent surgery to remove a blood clot near his right shoulder that was discovered following Friday night’s start against the Washington Nationals. Following the successful thrombolysis procedure, the big question is whether Wheeler can return this season.
“We don’t know,” manager Rob Thomson told reporters, including On Pattison’s Tim Kelly, ahead of tonight’s game against the Seattle Mariners. “We don’t know until we have further information.”
When asked if this could end Wheeler’s career, Thomson responded: “I don’t know.”
Rob Thomson on the timetable for Zack Wheeler…
— On Pattison (@OnPattison) August 18, 2025
(Via @TimKellySports) pic.twitter.com/kcv6qsH1Uj
Wheeler reported “a little heaviness” near his pitching shoulder following Friday’s start against the Nationals, where he threw 97 pitches in five innings while giving up two earned runs on four hits. Tests revealed a blood clot in his right upper extremity.
The shoulder issues began earlier this month. The three-time All-Star first reported soreness following his Aug. 2 start against the Detroit Tigers. The Phillies pushed him back in the rotation for extra rest before he pitched against the Texas Rangers on Aug. 10, then made his latest start Friday.
During Friday’s game against the Nationals, Wheeler still had some command issues, but his velocity appeared back as he was hitting 96-97 mph.
Phillies head athletic trainer and director of medical services Paul Buchheit doesn’t believe the initial shoulder soreness was connected to the blood clot.
“It’s hard to say, but I don’t think so,” Buchheit told reporters over the weekend, including The Philadelphia Inquirer’s Scott Lauber. “In talking with our doctors, it’s maybe independent. There weren’t these type of symptoms prior, so I do think they’re independent.”
Before the diagnosis, Wheeler was a Cy Young favorite once again. In 24 starts, he posted a 2.71 ERA in 149 2/3 innings and was leading the National League in strikeouts (195), WHIP (0.935) and strikeouts per nine (11.7).
The Phillies had been planning to deploy a six-man rotation since Aaron Nola returned Sunday, but those plans have been scrapped for now with Wheeler sidelined. The team wanted to give Wheeler, Ranger Suarez and Jesus Luzardo extra rest heading into the stretch run and playoffs.
Now with Wheeler out and his return uncertain, the Phillies’ World Series hopes have taken a significant blow.