In three starts so far this season, Phillies pitching prospect Andrew Painter has struck out 30 of 36 batters and has not allowed an earned run in 12 innings.

Time for a promotion?

Not yet, according to farm director Preston Mattingly.

“I think Andrew’s got a lot to work on still,” Mattingly said during a visit to Citizens Bank Park this week. “He’s like a lot of our other guys. He’s still working on getting his preparation down, getting his routine down, learning to pitch once a week, the consistency of that routine in the weight room, everything that goes into it.”

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Painter, 19 years old and drafted 13th overall by the Phillies last July, is scheduled to start again Saturday night for low-A Clearwater. In five one-hit innings last week against Tampa, a New York Yankees’ affiliate, the 6-foot-7 right-hander struck out 14 of 16 batters, including the final 13 in a row, and scraped 99.8 mph with his fastball.

Dating to his minor-league debut last August, Painter has struck out 42 of 54 batters in his professional career.

“It’s a guy who’s 6-foot-7 with four pitches, can command the ball pretty well for a guy his age,” Mattingly said. “You just say that out loud, and you don’t have to go a lot farther.”

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In time, perhaps after another few starts, Painter will join 2020 first-round pick Mick Abel at high-A Jersey Shore. Fellow right-hander Griff McGarry is also pitching in the BlueClaws’ prospect-loaded rotation.

But Mattingly said the Phillies want their minor-league pitchers to continue to build a workload. Painter isn’t any different. He threw 70 pitches against Tampa, the most he has thrown in a game so far.

“One thing we’ve tried to stress to our guys is, each time you go out there, you’re working on something and you’re trying to get better,” Mattingly said. “And something else comes up that you may not have experienced in your last start. There’s always something to get better at, and Andrew falls into the same category. He’s still got a lot to work on.”

Harper’s a 10

Thursday marked a generational red-letter day in baseball. Ten years ago — on April 28, 2012 — Mike Trout made his permanent return from triple A and Bryce Harper played his first major-league game.

Harper, then with the Washington Nationals, went 1-for-3 with a double in his debut at Dodger Stadium. His first hit came against Chad Billingsley.

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“Even though he was 19 years old, he was jumping in the mix,” former Nationals infielder Chad Tracy recalled last week. “He’d chirp in and let everybody know his opinion, and we’d kind of look around going, ‘What’s he doing?’ But at the same time, you loved it. He was such a good kid that nobody really told him to shut up and mind his business because you wanted him to feel comfortable.”

Harper has backed up the hype — and then some. A six-time All-Star and two-time National League MVP, he’s one of eight players to reach 250 homers, 100 steals, and 800 walks in his first 10 years, according to the Elias Sports Bureau. The others: Mickey Mantle, Mike Schmidt, Barry Bonds, Chipper Jones, Jeff Bagwell, Paul Goldschmidt, and Trout.

Catching on

Garrett Stubbs’ big game Wednesday — two hits, including his first career triple — was 11 days in the making. The backup catcher had not started a game since April 15, which can happen when the Phillies ride J.T. Realmuto for a lengthy stretch.

“It’s awesome to be able to go in there and have some success after being off for so long,” Stubbs said. “Cammy and Longo [assistant hitting coach Jason Camilli and hitting coach Kevin Long] do a great job of keeping me ready. It was nice to be back in there and good to help the team win.”

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Stubbs also nearly hit his first major-league home run in the eighth inning. He crushed a ball to deep right field that likely would have been out if the weather had been warmer.

“I hope so,” Stubbs said. “Because if that’s not going to be a home run on a hot day, then I’m not hitting any home runs. I thought I got it pretty good. I guess I’ll have to hit the weight room on these days before my next start.”

Extra bases

The Rockies made seven errors in the Phillies’ four-game sweep. ... Kyle Schwarber got his first day off Thursday since April 16. ... The Phillies’ powder-blue throwback uniforms arrived in time for their first midweek matinee home game. ... Starter-turned-reliever Francisco Morales continues to dominate in double A. He struck out five batters in two innings Wednesday and hasn’t allowed a run in 11⅔ innings to open the season. Opponents are 1-for-36 with 18 strikeouts against the right-hander, who likely will figure into the Phillies’ bullpen mix later this season. ... Pitching matchups for three 7:10 p.m. games against the Mets: Friday — Aaron Nola (1-2, 3.74 ERA) vs. Tylor Megill (3-0, 2.35); Saturday — Kyle Gibson (2-1, 3.47) vs. Taijuan Walker (0-0, 0.00); Sunday — Zach Eflin (1-1, 3.20) vs. Max Scherzer (3-0, 1.80).