Aaron Nola has made more starts (79) than any pitcher in baseball since the outset of the 2018 season. He has worked the second-most innings (486) and racked up the sixth-most strikeouts (549). Among 120 pitchers with at least 40 starts over the last three years, he ranks 10th in ERA (3.13).

By every measure, Nola has been elite.

And then September rolls around.

It’s one of the biggest riddles in Phillies camp, which opened Wednesday with pitchers and catchers working out in between the raindrops in Clearwater, Fla. It has stumped the last three pitching coaches and at least one manager. And while it doesn’t rank near the top of the list of concerns facing a franchise that hasn’t made the playoffs in nine years, solving it would go a long way to ending that dry spell.

How can a top-10 starter in all of baseball from April to August for three years running keep stubbing his toe so badly whenever the Phillies reach the final leg of the wild-card race?

“I’m not really sure, to be honest with you,” Nola said. “I’ve thought about it, obviously. The past few years it hasn’t gone my way.”

But it’s more than that. It’s like Nola morphs into his evil twin every Labor Day. Take away the last three Septembers and he is 30-9 with a 2.79 ERA in 62 starts. Isolate the last three Septembers and he’s 4-9 with a 4.44 ERA in 17 starts.

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To be fair, Nola isn’t alone. Since 2018, the Phillies are repeat offenders of sniffing the playoffs only to melt like fondue down the stretch. Nola is merely a symptom. He isn’t the problem.

But Nola’s late-season struggles came into full view last year.

The Phillies needed to win the season finale at Tampa Bay and get help from two other teams to claim the last wild-card spot in an expanded playoff field. The Milwaukee Brewers and San Francisco Giants cooperated by losing. But Nola, pitching on regular rest, didn’t survive the fourth inning in a 5-0 loss.

“That game obviously sticks with me because, one game away, we make the playoffs [if] we win,” Nola said. “Didn’t pitch well. It sat with me.”

Nola claimed he was healthy last September and in the two before that. And it wasn’t all bad. He blanked the Washington Nationals for eight innings last Sept. 1, then shut out the Miami Marlins in the first game of a seven-inning doubleheader 10 days later. But he gave up 11 runs in 15 innings over his last three starts against the New York Mets, Nationals, and Rays.

If there’s a common denominator between the last three seasons it’s that the Phillies leaned on their ace down the stretch each year. Although Nola never started on short rest, manager Gabe Kapler in 2018 and 2019 and Joe Girardi last year took advantage of days off to keep him on turn rather than giving him an extra day. Nola made 17 starts in the last three Septembers, tied with Patrick Corbin and Jack Flaherty for the most of any pitcher.

Girardi doesn’t know quite what to make of last year, as it relates to Nola or in general. Given all the anomalies of a 60-game schedule played during a pandemic, he might toss it completely if not for the fact that Nola stumbled late in the previous two seasons, too.

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Like others over the years, Girardi described Nola as “an extreme worker” in between starts. Is it possible the 27-year-old right-hander needs to dial it back late in the season? Girardi can’t say for sure. Because of the COVID-19 safeguards that were in place then and remain in spring training, he was unable to be as hands-on with pitchers’ between-starts routines last year.

“It’s something that we’ve looked at,” Girardi said. “One of the things that we will continue to try to put our finger on is when does he get tired and what are the best things to do to help him combat that.”

Layer on top of everything that all starting pitchers across baseball must rebuild the arm strength to withstand a full season after an abbreviated one and figuring out how hard to ride Nola becomes even trickier for Girardi and new pitching coach Caleb Cotham.

The Phillies have had internal conversations about using a six-man rotation for stretches of the season to ease the burden on their starters. Nola, predictably, prefers to stay on his usual five-day turn.

“I’d rather pitch on normal rest,” he said. “It’s what we’re all used to. It’s what I’m used to. I want to make 33-plus starts a year. This year, too. That’s always been my goal. I want to throw, get past the 200-inning mark and 30 starts every year. It’s kind of what I prepare my body for.”

There aren’t many pitchers who are better, at least from April to August.

“I’m going to stick with what I’m good at, what I need to work on in spring training, and treat September like I always do,” Nola said. “As any other month, you know?”

The Phillies wish that was the case.

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