ATLANTA -- The Mets learned Monday that they will be without one of their primary infielders for much of the remaining season. They did not, however, see that news as the impetus to call up top prospects Brett Baty or Mark Vientos. 

Luis Guillorme is expected to miss four to six weeks due to a moderate left groin strain, knocking him out for at least half of the remaining regular season. To replace him, the team called up veteran infielder Deven Marrero from Triple-A Syracuse. Marrero, 31, is capable of playing second base, third base and shortstop at a high level, which is why the Mets chose him over Baty or Vientos.

According to multiple people with knowledge of the situation, the Mets do not yet feel comfortable having Baty or Vientos play defensively in the Major Leagues. One source went as far as to say he does not expect either prospect to appear in the Majors this season.

“Of course it’s hard not to [think about it], especially when you’re one step away right now,” Vientos, the organization’s fifth-ranked prospect according to MLB Pipeline, said last week at Syracuse. “But I’m just trying to focus on the little things.”

“If it does happen, then I would go up there and do the same thing I’m doing down here: go through my daily work and try to be the best baseball player I can be for the team,” said Baty, Pipeline’s second-ranked Mets prospect and MLB's No. 18 overall prospect. “But right now, I’m not really focused on that. I’m just trying to get better.”

If the Mets are to call up any prospect for offensive support down the stretch, it is most likely to be catcher Francisco Álvarez, though that is also far from a certainty.

Unlike the division-rival Braves, who have received all-around contributions from recent callups Michael Harris II and Vaughn Grissom, the Mets see Baty and Vientos as bat-first prospects at this point in their careers. Their offensive profiles are legitimate: Baty entered Monday’s play slashing .364/.462/.364 in six games since earning a midseason promotion to Syracuse, after mashing 19 homers in 89 games at Double-A Binghamton, while Vientos is slashing .274/.354/.517 at Syracuse. They are former first- and second-round Draft picks, respectively.

But neither player profiles as an elite defender at third base. The Mets have tried both at first base and in the outfield in hopes of finding them permanent defensive homes.

Until that process further unfolds, team officials will sacrifice the offensive upside of Baty or Vientos in favor of Marrero, a glove-first shortstop who began the season with the independent league Long Island Ducks. Marrero signed with the Mets in late June and subsequently slashed .236/.325/.358 at Syracuse, playing three different infield positions. He has appeared in the Majors for the Red Sox, D-backs and Marlins.

Mets officials consider it important to have solid defensive coverage especially at shortstop, where Guillorme was serving as Francisco Lindor’s primary backup. Because the Mets use so much of their 26-man roster space on defensively limited platoon bats such as Daniel Vogelbach and Darin Ruf, team officials fear being caught flatfooted in the event of a Lindor illness or injury. While Eduardo Escobar is capable of playing shortstop in a pinch, he has been dealing with a left side injury of his own in recent days.

“We took everything under consideration,” manager Buck Showalter said, in what effectively amounted to a no-comment.

Regardless of the Mets’ roster decisions, the team will miss Guillorme, a standout defender at three positions who was also slashing .283/.355/.357 in 86 games. Guillorme, who had recently moved into a platoon situation with Escobar at third, strained his groin running the bases in Sunday’s win over the Phillies. He will not return until at least early to mid-September, though the Mets remain hopeful that Guillorme can help them down the stretch.