April 25, 2026, will mark the Major League return for Phillies ace Zack Wheeler. Wheeler missed all of September, plus the 2025 playoffs, last season, thanks to recovery from thoracic outlet syndrome. Months behind his surgery and minus one rib, the Phillies pitcher is now also behind his rehab assignment. Here’s a quick glance at how it played out.

The numbers

It was a mixed bag of results from Zack Wheeler across what was a lengthy rehab process for the right-hander.

Across five starts between Double and Triple-A, Wheeler struck out 23 over 20 and walked five. Wheeler conceded three home runs during his assignment, two of which came in one start while he was pitching in Northern New Jersey against the Yankees’ Double-A affiliate.

A 23% Whiff% rate in Triple-A was below what one would expect from Wheeler. However, his stuff was netting plenty of swings outside of the zone with a 37% Chase%. More strikeouts and more swing-and-miss (31.1%) with Reading.

The velocity

This will be one of the more fascinating things to watch when Wheeler returns to the Majors.

Wheeler’s fastball velocity — whether it be the sinker or the four-seamer — was down quite a bit compared to where he was pre-surgery. Let’s take a look at the boxplot:

He averaged close to 94 MPH in his first start back in late March with the IronPigs. Then, it dipped on average to below 93 MPH during his second and third outings with Lehigh Valley. Overall, his max velocity in Eastern Pennsylvania was 94 MPH.

Wheeler’s velocity ticked up a bit when he pitched in his first start. But in his last start down in Double-A, his fastball was sitting consistently 91-92 MPH during the game, yet again down from his career norms.

Now 35 years of age, Wheeler averaged 95-96 MPH every year between 2022 and 2025. However, those numbers weren’t seen in his rehab assignment.

Pitchers who came back from this type of thoracic outlet syndrome have had success. Merrill Kelly had the same type of surgery, one in which a rib was removed to remedy the vascular TOS.

Kelly isn’t a flamethrower per se, as he’s the kind of pitcher who relies on mixing speeds and looks to get hitters out. And since that surgery, he’s done that. Wheeler has the stuff to do that, and it’ll be interesting to see how everything plays out from here and out.

And right now, the Phillies could use a big jolt.

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