It was a rough night for Zack Wheeler and the Philadelphia Phillies at T-Mobile Park. Wheeler surrendered eight runs in four-plus innings, as the Seattle Mariners snapped the Phillies’ nine-game win streak.
“Just uncharacteristic,” said Phillies interim manager Don Mattingly on NBC Sports Philadelphia’s postgame coverage. “I just was talking to Caleb (Cotham), I haven’t been around him a whole lot, command was the biggest thing we see.”
The first inning set the tone for the night. After Luis Arraez’s single put the Phillies on the board, Wheeler got ambushed for five runs on the first six hitters. That put the club in a 5-1 hole they never climbed out of.
The Mariners cruised to a 9-2 win on the strength of Cal Raleigh’s three-homer night.
Phillies Interim Manager Don Mattingly on Zack Wheeler’s Rough Start vs. Mariners
GettyZack Wheeler surrendered four home runs against the Seattle Mariners. (Photo by Steph Chambers/Getty Images)
Zack Wheeler’s stuff was relatively fine in Seattle. The right-hander’s velocity and movement on his pitches were around his season averages. However, the Mariners made Wheeler pay for every mistake.
“His stuff still seems good. Just command and puts himself, puts us in trouble.”
Mattingly decided to send Wheeler back out for the fifth. That decision immediately backfired, as Cal Raleigh and Cole Young slugged back-to-back home runs off the right-hander, and more or less cemented the loss. Wheeler was pulled in favor of Alex McFarlane after the home runs.
“He wanted to go back out. I wanted him to go back out. We were going to keep it short, we weren’t going to let him go far. At that point we’re down, what is it, 6-2 and we’re in the fifth. So really needed that inning but didn’t get there.”
Wheeler finished his start with eight runs allowed on nine hits, five walks, and four strikeouts. Four of his nine hits left the ballpark, which tied a career-worst.
Mattingly isn’t overly concerned about Wheeler’s struggles.
“I’m not concerned that he’s not going to get where he needs to get to. Obviously anytime guys struggle…you’re concerned about it. You keep working to get better. But you’re not like ‘Oh, this guy’s lost it; he’s never going to be good again.’ So it’s like the kind of thing when I say I don’t worry about it, I don’t worry about that.”
Should the Phillies Be Worried About Zack Wheeler?
GettyZack Wheeler has a 5.60 ERA in the second half of 2026. (Photo by Steph Chambers/Getty Images)
The night marked another poor start for Zack Wheeler in the second half. The right-hander has surrendered at least four earned runs in four of his last six starts, albeit one was shortened to two innings by rain.
Over that stretch, his ERA has jumped from 2.16 to 3.40.
Since July 27, Wheeler has allowed 16 runs (15 earned) across 20.1 innings. He’s still striking out hitters at a 26.1% clip, but his walk rate has ballooned to 13.4%.
It hasn’t been an issue of velocity. In his last six starts, his fastball is averaging just under 95 MPH, right around his season average of 95.2. So the question is what’s causing Wheeler to walk hitters?
Fixing that issue will be important for the Phillies. Because they don’t stand much of a chance advancing in the postseason if Wheeler isn’t at his best.
Phillies’ Don Mattingly Gets Honest on Zack Wheeler’s Struggles After Mariners Loss