The Mets are about to grow slightly bigger and significantly more interesting.

The Mets plan to call up highly touted prospect Ronny Mauricio when rosters expand Friday, The Post’s Joel Sherman reported Wednesday night.

The 22-year-old, who has mashed much of this year and been a top prospect virtually since he was signed out of the Dominican Republic in 2017, will finally get his chance in a season that has become about the future.

Mauricio does not have a solid position but does have an intriguing bat.

The switch hitter posted an .852 OPS in 116 games with Triple-A Syracuse, which included 23 home runs and 24 steals.

He always has been a free swinger, though he has shown better plate discipline this season with an improved walk rate and a lowered strikeout rate.

But the natural shortstop has not found a second position that he plays consistently well.

With Francisco Lindor blocking the path at short, the Mets have moved Mauricio around without a ton of success.

The reports were not strong at second base, a position he began playing in late April, and he moved to both third base and left field with similar, underwhelming results.

For the past two weeks, Mauricio has shifted back to second base, where manager Buck Showalter said he “seems to be doing well.”

Showalter said that while Mauricio has handled the spot better the second time around, he made it clear defense had held him back.

“Defense is initially a priority with these guys,” Showalter said before the Mets beat the Rangers, 6-5, in 10 innings. “Got to be able to defend.

“You got to hit a whole lot to not be a good defender.”

The Mets surely hope Mauricio, with quick wrists that have invited Alfonso Soriano comparisons, will hit plenty. He hit at each level of the minors and had been the MVP of the Dominican Winter League this offseason.

The Mets were planning on meeting during Thursday’s off day to discuss their options for Friday, when a 26-man roster becomes a 28-man roster. Bringing up Mauricio means that Brett Baty likely will remain, for now at least, with Syracuse, unless the Mets bring up the young third baseman and demote someone else. Before news spread that Mauricio’s time had come, Showalter had said that Mauricio and Baty were both “under consideration.”

There was wonder when Mauricio would be called up not just because of his talent but because of the Mets’ alternatives. Danny Mendick and Jonathan Arauz, who do not figure to have long Mets futures, have received plenty of time at second since the Mets sold at the trade deadline.

The Mets can get a glimpse at the future and see what their No. 4 prospect, according to MLB Pipeline, can do. They will test out Mauricio’s toolsy game, even if the glove will be a work in progress.

Baty also came up with a poor defensive reputation, but his bat has been a bigger issue than his third-base defense through his first season.

The 23-year-old crushed Triple-A pitching and forced his way to the majors by mid-April, but he could not translate the minor league success into a major league breakthrough.

Baty hit just .216 in 86 games with the Mets, his power (seven homers) mostly absent as he struggled to lift the ball.

He did not seem to be making progress and went 0-for-18 in six August games, prompting a demotion.

Since reporting to Syracuse, Baty statistically has been solid, entering play with an .824 OPS boosted by five home runs in 16 games. Arauz, Mendick and Mark Vientos have seen time at third base since Baty was sent down.

Presuming the Mets select from players on their 40-man roster, their pitching options for a call-up are less intriguing. Joey Lucchesi or Grant Hartwig could return to Queens.

The Mets might not win much in September, but Mauricio thriving could represent a positive development.