From left, Mets infielders Ronny Mauricio, Francisco Lindor and Brett Baty...

From left, Mets infielders Ronny Mauricio, Francisco Lindor and Brett Baty before a spring training game against the Cardinals on Feb. 27 at Roger Dean stadium in Jupiter, Fla. Credit: Newsday/Alejandra Villa Loarca

The Mets’ attempted youth movement will pick up in a major way Friday, just not in the context they anticipated. 

A season that began with four almost-ready position-player prospects representing potential in-season, in-house improvement for a probable contending team will reach September with that quartet just trying to make a good impression for next year.

In addition to promoting infielder/outfielder Ronny Mauricio to the big leagues for the first time, the Mets also will bring third baseman Brett Baty back on Friday, a source said. They will join fellow rookies Francisco Alvarez and Mark Vientos on the roster and — some days, inevitably — in the lineup. 

Righthander Jose Butto will join the team, too. He is likely to work out of the bullpen. 

“Once [Mauricio] gets called up, you’re going to start seeing some extraordinary things because of how great of a player he is, how talented he is,” Alvarez told Newsday through an interpreter Thursday night, before the news of Baty’s return. “For me personally, it’s going to be another comfort thing for me, because he’s like my brother. So to have him gives me a little bit more confidence to continue talking more, talking to all of the guys.” 

After a month a post-trade deadline lineup cards filled out with a variety of random players, manager Buck Showalter could be looking at a regular defensive alignment that includes Mauricio at second, Baty at third and Alvarez at catcher (plus Vientos at DH). That would be in addition to, of course, Pete Alonso at first, Francisco Lindor at shortstop, Brandon Nimmo in center and Jeff McNeil in left or right. 

A consistent arrangement such as the one above would allow the Mets to get a better sense of what they have internally before deciding which areas of the roster they need to supplement over the offseason. 

Baty’s comeback came quickly. The Mets demoted him to Triple-A Syracuse on Aug. 7 after months of struggles offensively and defensively. He hit .216 with a .289 OBP and .331 slugging percentage, so organizational decision-makers, deeming his confidence negatively impacted, decided he stood to benefit from a reset.  

He will need to prove that it can translate to major-league success, but Baty did well statistically during his few weeks in the minors. That included a .246/.329/.493 slash line. 

Mauricio, 22, similarly has hit well at the highest level of the minors, but the Mets declined to call him up until now because they wanted to see certain signs of progress on both sides of the ball. 

Defensively, especially, this year has been an adventure for Mauricio, long one of the Mets’ top prospects. A shortstop by trade, Mauricio mostly has played second base lately, in addition to dabbling with leftfield and third base. 

He is the first in what might be a long line of Mets shortstop prospects who have to move off the position in deference to Lindor, a two-time Gold Glover under contract through 2031. 

Working with a new and inexperienced double-play partner will require an adjustment period, Lindor said. 

“We’re going to feel out each other. That’s a fact,” Lindor told Newsday on Thursday. “We’re going to have to get to know each other, take ground balls together, figure out his style. We’ll just communicate. Wherever he plays — second, short, third — and wherever I play, I’m just looking forward to it.” 

Lindor called Mauricio “a quiet kid,” but Alvarez — who played with Mauricio extensively in the minors — warned against drawing conclusions based on his outward demeanor. 

“Sometimes people think that he’s not like this energetic guy because he doesn’t talk much,” Alvarez said. “Sometimes you’ll see him and you’re like, man, he doesn’t really talk much, maybe he doesn’t care. But then you have a conversation with him and you’re like, man, he’s paying attention to every part of the game and he really cares.” 

Lindor said: “If he’s up here, that means he’s ready, so I’m looking forward to it . . . I’ve been waiting for him, so I’m happy he’s getting his chance.”

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