ATLANTA — The energy that had buoyed the Mets during their consecutive winning streaks over the last three weeks was conspicuously absent Tuesday. But the sting of a bad night at the office was dull in comparison to the possibility their best pure hitter will be lost for an extended period.

Jeff McNeil sustained a left hamstring injury trying to beat out an infield single in the ninth inning of the Mets’ 5-3 loss to the Braves at SunTrust Park, and now manager Mickey Callaway and Co. await further evaluation to tell them if he will play again anytime soon.

McNeil, who is batting .332 — he began the night second in the NL in hitting — is scheduled to undergo an MRI exam on Wednesday that should give the Mets clarity.

“It didn’t feel great, but I don’t think it’s terrible,” McNeil said. “We have no timeline. I guess we’ll see how it feels in the morning.”

McNeil indicated he felt the leg tighten before he reached the bag. It’s the same hamstring that cost him 12 games on the injured list beginning May 22.

“It sucks,” McNeil said. “The team is playing well. I just want to contribute and hopefully this is something real short and I’ll get back on the field.”

The Mets’ IL already includes Robinson Cano (torn left hamstring), Dominic Smith (stress reaction in left foot) and Brandon Nimmo (herniated disk in his neck).

On this night Zack Wheeler was flat, and the lineup behind him equally unimpressive. A game that had a blah feel in the suffocating Georgia humidity ended with the Mets contemplating a two-game skid for the first time since their recent rebirth.

The Mets (61-58) hadn’t lost two straight since the Giants beat them in consecutive extra-inning games on July 18 and 19. Since then the Mets were 17-4, a stretch that had included winning streaks of seven and eight games. The loss dropped the Mets two games back in the race for the second NL wild card.

As much as the Mets tried to make it a game against the Braves bullpen, the significant rally they needed became just a trickle in the eighth, as Anthony Swarzak retired pinch-hitter Joe Panik with the tying runs on base. The Mets had scored twice in the inning, which included Juan Lagares’ fourth hit in a 4-for-4 night, an RBI single off Freddie Freeman’s glove. In addition to Swarzak, another former Mets reliever recorded a big out in the inning, as Jerry Blevins induced Michael Conforto to hit into a fielder’s choice. In the ninth, Mark Melancon was perfect in recording the save.

After 15 scoreless innings to begin the second half, Wheeler turned in a clunker, allowing five earned runs on 12 hits and two walks over five innings. The right-hander was removed after 91 pitches.

“I just didn’t have it tonight,” Wheeler said. “It stinks. We’re on this run and I just didn’t give us a chance to win, really. The bullpen kept us in it and those guys kept on battling, but I take this one and this one is on me.”

Wheeler’s only real easy inning was the third, when he got Charlie Culberson to hit into a double play. The Braves extended their lead to 4-1 in the fourth, with Ronald Acuna Jr. smoking a leadoff homer on a full-count fastball. Acuna’s homer was his 34th this season as he continues to lurk in the National League MVP conversation.

In the fifth, Ender Inciarte swung on a 3-0 pitch and banged a grounder off the first-base bag that went for an RBI double, increasing the Mets’ deficit to 5-1.

Max Fried’s leadoff double in the second on a ball J.D. Davis couldn’t handle on a bounce led to the Braves taking a 3-1 lead on Josh Donaldson’s RBI single. Wheeler faced eight batters in a first inning in which he allowed two runs on four hits and a walk.

The lefty Fried frustrated the Mets by allowing one earned run on six hits and three walks over six innings.

“We didn’t give up tonight,” Callaway said. “We made it interesting and we made them use some relievers they probably didn’t want to use, which helps us out for [Wednesday].”