The evolution of Zack Wheeler: How he’s become the ace of aces during a run that rivals any Phillie in history

Wheeler seems to be aging in reverse, pitching better in his 30s than his 20s. Let’s examine his journey, through the eyes of the pitching coaches and catchers who know him best.

Zack Wheeler has a 2.85 ERA and a 1.008 WHIP through 151 starts with the Phillies.Read moreYong Kim / Staff Photographer

by Scott Lauber

Published July 11, 2025, 10:13 a.m. ET

One month into the 2021 season, the label of “best pitcher on the planet” could reasonably be attached to one — and only one — person.

So, yes, Dave Eiland realized the height of the comparison.

And he made it anyway.

“I’m not making the statement that Zack Wheeler’s just as good as Jake deGrom,“ the former Mets pitching coach said back then. ”That’s not what I’m saying. What I’m saying is, he’s starting to wander around that same neighborhood."

Four years later, Eiland concedes he shortchanged Wheeler.

Because although deGrom was utterly Koufaxian from 2018 through the middle of the 2021 season, Wheeler has paired dominance with durability to eclipse his friend and former teammate — and just about everyone else in baseball — and put together a six-year run that rivals that of any Phillies pitcher in the last 100 years.

Period. Full stop. Reality, not hyperbole.

Consider: Entering his final start before the All-Star break, scheduled for Saturday night in San Diego, Wheeler has made 151 starts for the Phillies. His numbers:

2.85 ERA, 1.008 WHIP, 945⅓ innings, 1,047 strikeouts, 212 walks

Since 1925, 18 pitchers started at least 151 games for the Phillies. Only Jim Bunning, Robin Roberts, Steve Carlton, and Chris Short had a better ERA than Wheeler over a 151-start span. Only Carlton racked up more strikeouts; only Roberts had fewer walks. They all had more innings, but that’s a 21st-century-pitching issue, not a Wheeler issue. And Wheeler whips them all in WHIP (walks/hits per inning pitched).

Now, consider this: Wheeler’s park-adjusted ERA with the Phillies is 148, meaning he’s 48% better than league average since the start of the 2020 season. That would be the best ERA+ over a six-year span by any Phillies starter in the last 100 years. Roberts’ best was 135; Carlton’s 133.

And this: Wheeler has 30.2 wins above replacement, based on Baseball-Reference’s calculation, with the Phillies. The only Phillies starters with more bWAR in a six-season span since 1925 are Roberts (46.9, 1950-55) and Carlton (31.1, 1972-77; 32.4, 1977-82).

Get the point?

Wheeler, a two-time Cy Young Award runner-up, is making $42 million per year through 2027, the third-highest salary ever for a pitcher (non-Shohei Ohtani division). He recently received his third All-Star selection. But with the 95th All-Star Game poised to descend upon his hometown Tuesday night, the 35-year-old Atlanta native decided not to pitch even though he was a prime candidate to start for the National League.

Here, though, is the amazing part: Wheeler’s rise to the pinnacle of the sport came after he (a) lost two seasons to injuries; (b) left the Mets and deGrom’s shadow; (c) turned 30; and (d) turned from a top prospect with a blazing fastball into a six-pitch artist.

“If there’s one game I had to win, Game 7 World Series, or just one game regardless of the stakes, there’s not another pitcher in baseball I’d want to start that game over Zack,” Eiland said by phone this week. “There’s really not. Not Jake. Not Gerrit Cole, if he’s healthy. Not [Paul] Skenes. Not anybody.”

Somehow, Wheeler has managed to age in reverse, pitching better in the first half of his 30s with flecks of gray in his beard than he did in his 20s when he could barely grow a wispy mustache. How did it happen? How did Wheeler become the ace of aces? Let’s examine his evolution, through the eyes of three pitching coaches and three catchers who know him best.

‘Best fastball I ever caught’

Tommy Joseph still remembers the first start.

It was April 11, 2010, in Greensboro, N.C. Wheeler was 19, less than a year out of East Paulding High School in Dallas, Ga. As a senior, he went 9-0 with a 0.54 ERA and 151 strikeouts in 77⅔ innings. He struck out 15 batters in one game. He pitched a no-hitter in the Georgia state playoffs. The Giants drafted him with the sixth overall pick in 2009, one spot ahead of the hometown Braves.

Everybody knew who Wheeler was when he arrived at low-A Augusta — 150 miles east of Atlanta — to begin his career in pro ball. He started the fourth game of the season amid the typical top-prospect hoopla.

And he lasted all of six batters.

Wheeler issued three walks, gave up a two-run single, and got only one out when manager Dave Machemer came out with the hook after 35 pitches.

“He sat in the dugout afterward and did not move for the rest of the game and just like stared off into space,” said Joseph, the former Phillies first baseman who roomed with Wheeler in the Giants’ farm system in 2010 and 2011. “You could kind of tell that it was the first time that something hadn’t gone his way — and he did not handle it well.”

There were other challenges. Wheeler walked 16 batters in his first six starts. He spent six weeks on the injured list when the nail on his right middle finger ripped away from the skin bed, an injury that cropped up a few times early in his career. Joseph called it “probably the weirdest thing I’ve ever seen a guy experience.“

But hidden within the early adversity, there were lessons.

“My biggest thing with him coming out of high school was just being able to handle failure when you get hit,” said former major league reliever Steve Klein, Wheeler’s pitching coach in Augusta. “Young kids that throw hard in high school, you dominate, and then you get to the pro level and now guys start hitting the ball. What’s your reaction to it? Do you work on your off-speed? Do you just try to throw harder?

“Zack handled the failure really well. His whole demeanor, he was the same then as he is now, not very excitable, very quiet, reserved. He reminds me of a Clint Eastwood character, you know?”

Indeed, even then, Wheeler had a stare that could melt steel and a no-nonsense, almost gruff facade. Then, like now, his idea of a great meal involved fast food.

Joseph, who grew up in Arizona, hung out with Wheeler’s high school buddies when they visited him in Augusta or on the road in nearby Rome, Ga., or Savannah. But Joseph also discovered that Wheeler intentionally kept a small inner circle: his parents, Barry and Elaine, played amateur baseball and softball; his oldest brother, Jacob, and middle brother Adam, a 13th-round pick of the Yankees whose career was short-circuited by arm injuries; and eventually his wife, Dominique, with whom he now has four children.

That’s it.

“He doesn’t let people in, and he does a good job controlling that,” Joseph said. “He’s remarkable, in terms of really how mentally stable he is. He’s as calm and as confident as anybody I’ve ever met.”

Wheeler’s control improved on the mound, too, even if the Giants rarely took off the training wheels in that first pro season. He completed six innings only once in 13 starts.

But there was no denying the quality of Wheeler’s stuff, especially the fastball.

With the advent of Statcast, the secret to Wheeler’s heater has been revealed over the last 10 years. He gets elite extension (7.2 feet, on average) through his delivery, which causes his 95- to 97-mph octane to get on hitters even more quickly.

Fifteen years ago, though, Joseph knew only one thing.

“He had the best fastball I ever caught,” said Joseph, now the Orioles’ assistant hitting coach. “It’s just electric. Now we know it’s got these unique metrics, right? But it’s evolved literally into the best fastball in Major League Baseball. There’s a lot of really good ones out there, but I don’t think any of them compare to Zack.”

It would be a few more years before the rest of Wheeler’s repertoire caught up.

‘Let it eat’

The Giants were in the midst of defending a World Series crown when they went all-in at the 2011 trade deadline by acquiring All-Star center fielder Carlos Beltrán from the Mets.

The price: Wheeler.

Two years later, New York called up Wheeler for his major league debut in the finale of a doubleheader in Atlanta (where else?). He walked five batters but struck out seven in six scoreless innings.

“It’s a guy who had all the talent in the world — electric fastball, really good spin on the breaking ball,” said Anthony Recker, who caught Wheeler’s debut. “He’s always had that. But mentally he would struggle a little bit. He didn’t always show it on the mound, but he’d get really frustrated and he would allow things to kind of snowball.”

Looking back, maybe there was a reasonable explanation. Because for all the prospect hype around Wheeler with the Giants, the billing for him with the Mets was even greater.

Not only did he get traded for Beltrán — straight up, no less — but he was lumped in with Matt Harvey, deGrom, Noah Syndergaard, and Steven Matz as the Next Great Starting Rotation. They embodied hope for a franchise that hadn’t made the playoffs since 2006. They were the can’t-miss heirs to “Generation K,” the mid-90s trio of Mets pitching prospects who flamed out.

“When I got there [in 2018] I tried to play it down a little bit,” Eiland said. “I took some flak for it, but I mean, listen, man, let’s let these guys go out and do something first before we put all five of them in the Hall of Fame.”

Wheeler had a solid rookie season in 2013, then took a step back in the first half of 2014 before finishing strong.

And then, in spring training of 2015, he blew out his elbow.

It took 24 months for Wheeler to make it back, and even more time to unbridle his fastball again. Eiland said the turning point came in a bullpen session in May in Cincinnati after Wheeler gave up eight runs in his previous start.

“I said, ‘You’ve got 95-96 in there. Why are you settling for 92-93? Let it go. Let it eat. It’s in there,’” Eiland recalled. “And then his next start, he went out and that’s kind of when he got off and rolling. You could see it in his eyes and his body language, and you could see it in his pitches.”

There were still times when Wheeler would lose focus and let an inning unravel. In 2018 and 2019, he struggled in the first half but pitched great after the All-Star break. Consistency was elusive.

But the Phillies saw upside and gave Wheeler a five-year, $118 million contract, then the third-largest free-agent pact in team history. First, they tried to sign Kyle Gibson, but he preferred to be in the Midwest. They thought Hyun-Jin Ryu had similar room for growth as Wheeler but more risk.

Mostly, they thought Wheeler would benefit from leaving New York.

“The Mets didn’t really believe in him very much,” Eiland said. “When I first got there, all I heard from some people in the front office was, ‘Wheeler’s pitching good now. We’ve got to trade him.’ They were talking about trading him from the day that I walked in the door.”

Said Recker: “It was like a switch flipped as soon as he went over there [to Philadelphia]. I think there was some pressure off of him. Just the way that I’ve seen him kind of settle in to who he is. The guy is so stoic out there. Nothing fazes him. It’s kind of that maturation process he went through, and it’s done wonders.

“That, combined with the fact that he’s just always looking to get better. It’s really impressive that even at his age he’s still finding ways to do that.”

It helps, too, that Wheeler met J.T. Realmuto and Caleb Cotham.

‘He’s a complete pitcher’

With the Phillies, Wheeler found his zen.

It started with Realmuto. They worked together for the first time in Wheeler’s first Phillies start, the second game of the abbreviated 2020 season. That’s when Wheeler realized there’s never a need to not follow Realmuto’s lead.

A reminder came this past April 29 against the Nationals in Citizens Bank Park. Wheeler threw 106 pitches, all but one of which was called by Realmuto. The one that wasn’t: a sinker that Luis García Jr. launched for a two-run homer to cap a 10-pitch at-bat. (Realmuto wanted a splitter.)

“That’s why I don’t shake J.T. off,” Wheeler said.

Realmuto has been behind the plate for 85% of Wheeler’s regular-season Phillies starts — and all 11 postseason starts, in which Wheeler has a 2.23 ERA.

And if Wheeler had his way, he’d never work with another catcher again, perhaps the best endorsement for the Phillies to keep Realmuto beyond this season.

“He’s carried me ever since I’ve been here,” Wheeler said.

Said Realmuto: “He’s evolved so much that he’s gotten better really across the board. His stuff’s gotten better, his command’s better. He’s added pitches. He understands when we’re trying to freeze hitters or get guys to chase. He’s a complete pitcher, and when he came here, he wasn’t as complete as he is now.”

A year after Wheeler joined the Phillies, they hired Cotham as pitching coach. Cotham is only 2½ years older than Wheeler. They were drafted the same year, four rounds apart.

Cotham is schooled in all the modern metrics and pitch designs for which an old-school workhorse like Wheeler would seem to have no time. But Wheeler is also acutely self-aware. He knew his fastball would lose a few ticks as he got older, and sure enough, when it happened in 2022, he asked for ideas about how best to evolve.

Wheeler and Cotham agreed in 2023 to turn his hard slider into a sweeper, with more horizontal movement to get more swings and misses. A year later, they added a splitter to give him another weapon against lefties.

“You can see how he’s evolved his arsenal,“ Cotham said. ”He’s open-minded, but he guards what he is at its core. He’s going to throw two [types of] fastballs. He’s going to come at you. But there’s the curiosity of, how do I get a little bit better and find an edge every year?

“From a physicality standpoint, he’s still at the top of the charts. But he is getting older, and there are days where he doesn’t have the 99 [mph]. He’s now, ‘Hey, maybe the days that I’m 96-97, can I understand how my fastball is shaped?’ He’s definitely more of a pitcher, but it’s layering on very simple things.”

Wheeler has also placed his trust in head athletic trainer Paul Buchheit, whose hiring coincided with Wheeler’s arrival in the 2019-20 offseason. He has gotten close with Aaron Nola.

It’s almost like Wheeler could pitch in Philadelphia forever.

But when he signed a $126 million extension before last season, Wheeler insisted it will be his last contract, that he has no interest in playing into his 40s. Not with four young children at home. His stance hasn’t changed. He has no intention of playing beyond 2027, even if he’s still at the top of the sport.

Does anybody actually believe he’d walk away?

“No, there’s no way. You can’t do that, right?” Joseph said. “Because when you’re one of the best in the game, that’s normally when the sport is the most fun. So, I would call bull on it.

“But if anyone would do it, it would be him. And no one would ever hear from Zack again.”