Mets' Luis Guillorme walks through the dugout after he scored...

Mets' Luis Guillorme walks through the dugout after he scored against the Philadelphia Phillies during the fourth inning of an MLB baseball game at Citi Field on Sunday, Aug. 14, 2022. Credit: Kathleen Malone-Van Dyke

ATLANTA — The Mets’ third-base situation entered a state of significant uncertainty Monday when Luis Guillorme landed on the injured list for at least a few weeks, recent former Long Island Duck Deven Marrero was called up from the minors and Eduardo Escobar was well enough to start again — and that was just the goings-on for the day.

“Then we’ll see if we want to make any adjustments before tomorrow,” manager Buck Showalter said.

Guillorme, who hurt his left groin while running the bases Sunday, had an MRI that showed what the team called a moderate strain. That injury typically sidelines a player for four to six weeks, a Mets spokesman said. Such a timeline would put Guillorme on track to return in mid- or late September.

Showalter sought to downplay the loss of Guillorme but also mentioned him in the same context as a couple of All-Star sluggers.

“The Phillies just played without [Kyle] Schwarber. The Yankees play without [Giancarlo] Stanton,” he said. “These guys [Atlanta] have played without people [including Ozzie Albies]. Yeah, he’s valuable. So is Jacob deGrom . . . it is what it is. But he’s done a lot of things for us. We’ll try to hold the fort down.”

That response underscored the increased importance of Guillorme to this season’s Mets. For years a sure-handed backup at second base, shortstop and third base, Guillorme had shown enough offensively to earn the bulk of the third-base playing time in recent weeks. He has a .283/.355/.357 slash line in 86 games — already by far the most in his career.

“Did you think you’d be saying this in August about Guillorme?” said Showalter, a fan of his since early in spring training. “He’s a valuable guy. But so is some of the people that we’ve gotten back. Trevor May’s back, Jake’s back. We’ll see. It’s part of baseball. It is what it is.”

The Mets considered calling up third-base prospect Brett Baty, according to a person familiar with their thinking, but they decided against it because they view him as not ready for the majors, particularly defensively. Baty, 22, was promoted to Triple-A Syracuse last week.

They did not consider calling up Mark Vientos, the source added. As a righthanded hitter who plays the corner infield spots (and not much third lately), Vientos didn’t fit what the Mets were looking for in replacing Guillorme, a defensively versatile lefthanded hitter.

Thus they added Marrero, 31, a light-hitting utility infielder (who coincidentally went to the same South Florida high school as Vientos, but eight years earlier). He was batting .236 with a .684 OPS with Syracuse after signing with the Mets in June. Before that, he was playing with the Ducks of the independent Atlantic League.

Marrero is a career .194 hitter with a .534 OPS over parts of six major-league seasons with the Red Sox, Diamondbacks and Marlins.

All that seemingly leaves Escobar as the regular third baseman again. He has performed poorly enough against righthanded pitchers this year that Showalter has been benching him in favor of Guillorme. Still dealing with the soreness in his left side that limited him over the weekend, Escobar has been steadily improving, Showalter said.

“He’s trending in that direction. Physically, he seems to be in a good spot,” Showalter said. “He’s playing third base tonight, and we’ll see what tomorrow brings.”

Before the Mets officially decided on Marrero, Showalter noted that they were looking at “a lot of options” to replace Guillorme, including “some internally.”

“Whether [general manager Billy Eppler] and somebody else looks externally,” he said, “that’s up to them and what they deem best.”