New York Mets shortstop Amed Rosario hits an RBI single...

New York Mets shortstop Amed Rosario hits an RBI single against the Pittsburgh Pirates during the first inning of an MLB baseball game at Citi Field on Sunday, July 28, 2019. Credit: Kathleen Malone-Van Dyke

PITTSBURGH — The Amed Rosario centerfield experiment, which had barely begun, has been paused indefinitely.

With Rosario’s improved play at shortstop recently, the Mets have scrapped the idea — at least for now — of moving the lifetime infielder to the outfield.

“The one thing we did focus on and knew we were going to focus on before we did anything with Rosie was to continue to try to help him develop at short,” manager Mickey Callaway said on Friday. “It seems like that’s really paying off. I think for now, we’ll probably continue just to focus at short and go from there.”

Rosario was a defensive mess to begin the season. He had made 14 errors heading into play Friday (tied for fourth most in the majors) and had been worth -15 Defensive Runs Saved (second worst among shortstops).

But since May 7, Rosario has made only four errors and has shown an improved ability to reach ground balls to his left, an area of focus in his work with infield coach Gary DiSarcina.

Callaway said Rosario’s improvement could be the product of several factors, including his extensive pregame work and perhaps the 23-year-old’s increased maturity, plus a recent hot stretch at the plate that has allowed him to relax in the field.

“Maybe he’s really starting to click,” Callaway said. “You always find that ‘a-ha’ moment in your career and then you start to take off. Maybe he’s found his.”

And maybe the centerfield talk served as motivation.

“He was always saying, ‘Oh, yeah, I’d love to do it, whatever you guys want,’ ” Callaway said. “But I’m sure deep down inside he knows he’s a shortstop, he wants to be a shortstop and he can be a really good one, as we’ve seen. So I’m sure that can be part of it.”

The Stro Show begins

Callaway had no fears of rust for Marcus Stroman, whose Mets debut on Saturday will be his first start in 11 days.

“He has such a good feel, he’s such a great athlete, I’m not really concerned about it,” Callaway said. “He can probably step out of bed in the offseason and start throwing his curveball for strikes. That’s the kind of feel he has. You normally worry about that with guys that are really tall and lanky. You’re worried about their body syncing up. He has such good body control that I’m not really worried about it.”

Stroman spent part of Friday afternoon perusing his teammates’ bats Goldilocks style, looking for one just right. An American League pitcher until now, Stroman is 3-for-17 with a double and a homer in his major-league life.

Mazza returns

The Mets made a minor bullpen swap, recalling Chris Mazza from Triple-A Syracuse and sending Stephen Nogosek back in his place. Callaway said the Mets sought Mazza’s length — he had been starting in the minors — leading up to and during their Monday doubleheader with the Marlins.

In part because the rotation and rest of the bullpen have been so good lately, Nogosek hadn’t pitched since July 24.

“We also wanted to get him down there and get him going, because we feel like he can help us moving forward,” Callaway said.

Extra bases

MLB made four scoring changes on plays involving the Mets from July 25 through Thursday. The net results: an extra RBI for Wilson Ramos (on his single in the sixth inning Thursday), a hit taken away from Todd Frazier, an error for Rosario and a single for Michael Conforto … Robinson Cano is the 14th player in major league history to hit double-digit homers in each of his first 15 seasons. The only other second baseman to do that: Jeff Kent … Pittsburgh manager Clint Hurdle (two-game suspension) is out through Saturday as part of the fallout from the Pirates-Reds brawl on Tuesday night.