The Phillies miscalculated their fifth-starter plan. Where do they go from here?

SAN FRANCISCO — Two weeks after the World Series ended last year, the Phillies convened organizational meetings at Citizens Bank Park. Among the agenda items: remaking the starting rotation.

It was part mathematics, part projection.

Because the latter is inherently inexact, the planning tends to begin with the former. In the Phillies’ case, it took 1,429 innings pitched to get through a 2022 regular season that netted 87 wins and a wild-card berth. Of those, 896⅔ came from starters. And of those, 288⅓ came from Kyle Gibson (167⅔), Zach Eflin (68), and Noah Syndergaard (52⅔), all of whom were free agents.

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Then came the projection. As much as the Phillies love their prospect troika of Andrew Painter, Mick Abel, and Griff McGarry, they knew that none was ready to take on Gibson’s workload. So, they set out to sign a veteran free agent and landed Taijuan Walker, who averaged 158 innings over the last two seasons with the Mets.

The question, then: Was there enough internal depth to cover the roughly 130 innings that remained? Dave Dombrowski offered the answer in a Nov. 16 news conference.

“We’re keeping a spot open,” the Phillies president of baseball operations said, “for a youngster.”

Seven weeks into the season — and after the demotion Tuesday of struggling Bailey Falter to triple-A Lehigh Valley — it’s clear they miscalculated.

Internally, the Phillies thought it was reasonable to budget a chunk of those 130 innings for Painter, the consensus top pitching prospect in the sport. He got to 103⅔ innings in the minors last year. A generally accepted guideline within the industry is that a year-over-year innings bump of 30% is a safe way to build a workload for pitchers who are under 25 years old.

But Painter sprained an elbow ligament in spring training and is working his way back slowly by playing catch in Florida.

Injuries happen, of course. The Phillies knew that. But Falter worked 76⅔ innings as a starter last season — and delivered a 3.76 ERA. And with lefties Cristopher Sánchez and Michael Plassmeyer in triple A, plus Abel and McGarry rounding out their development, the Phillies were comfortable with their depth.

So far, Sánchez and Plassmeyer are struggling with Lehigh Valley; Abel is still harnessing the command of his electric stuff in double A; McGarry is recently back from a season-opening muscle strain in his side.

Oh, and Falter, the presumed fifth-starter firewall, is 0-7 with a 5.13 ERA after giving up six unearned runs in the second inning — exacerbated by six hits, including a three-run homer from Michael Conforto — in Monday night’s 6-3 loss to the Giants.

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“I’ve changed up my mechanics, I’m trying to throw harder, just a whole bunch of things,” Falter, the first Phillies pitcher to lose his first seven decisions in a season since Jerad Eickhoff in 2017, said Monday night before getting word of his demotion. “I’m just going to go back to what got me here.”

And if he can’t find it in triple A or it isn’t enough, well, Dombrowski will go shopping at the trade deadline for the starter that the Phillies didn’t deem necessary last winter.

It’s too early to know how the market will look. Within the typical rhythm of a baseball season, teams take until Memorial Day to assess what they have, spend most of June pursuing what they need, and don’t get serious about making offers until almost the All-Star break. The trade deadline is Aug. 1.

Dombrowski has acquired a starter at each of the last two trade deadlines. Last year, it was Syndergaard, who went 5-2 with a 4.27 ERA in nine starts. In 2021, it was Gibson, who was under contract through 2022 and largely reliable as a back-of-the-rotation starter until a dreadful September last year hiked his Phillies ERA to 5.06.

Here, then, are a few teams and pitchers to watch for the next two months, with the disclaimer that it’s still very, very early:

A four-game winning streak entering Tuesday night has calmed things in St. Louis after a 13-25 start and controversy over highly paid catcher Willson Contreras’ role. And if any division will forgive a poor six-week stretch, it’s the National League Central.

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But keep an eye on the Cardinals anyway. Because Jack Flaherty and left-hander Jordan Montgomery are eligible for free agency after the season. Montgomery, 30, was a deadline addition last year and helped St. Louis win the division by posting a 3.11 ERA in 11 starts.

The American League’s version of the Cardinals, they were 14-28 entering play Tuesday and had only one three-game winning streak.

“Put it on me,” longtime general manager Rick Hahn recently told reporters — and if the White Sox keep sinking, even in a winnable AL Central, ownership might do just that.

Regardless, it’s difficult to imagine Chicago selling low — or even at all — on 27-year-old ace Dylan Cease, who is under control through 2025 and has a 4.86 ERA through nine starts. But what about Lucas Giolito, who turns 29 in July and can be a free agent at season’s end?

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Phillies officials were certain that Painter would make an impact at the major league level this season. They remain confident that it could still happen.

“He hasn’t had any setbacks,” manager Rob Thomson said last week while Painter was in Philadelphia for a check-in with the team’s medical staff. “Everything has been going fine.”

Painter’s throwing program is progressing at a deliberate pace. Last week, he played catch from 120 feet. It’s unclear when he will try to throw from a mound, and agent Scott Boras has tried to preach patience with the 20-year-old.

It’s in everyone’s interest to maintain a conservative timeline. But if Painter is ready to make his anticipated major league debut by, say, the beginning of August, he could be an even bigger X-factor than a deadline addition.

And then the Phillies would have the internal fifth-starter solution that they were banking on all along.

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