ATLANTA -- Each flip of the page-a-day calendar brings a new test for the Mets. Earlier this month, the question was whether the Mets could beat up on a run of inferior teams. (They could.) Then it was whether they could beat playoff-caliber teams. (They can, and did.)

Tuesday presented a new challenge. Playing on a sweltering Georgia evening that reached 94 degrees at first pitch, the Mets dropped a 5-3 game to a Braves club that has held an uncontested National League East lead for more than two months. They also lost second baseman Jeff McNeil to a left hamstring injury of unknown severity.

• Box score

“It stinks,” starting pitcher Zack Wheeler said. “We were on this run and I just didn’t give us a chance to win, really.”

One of the keys to New York’s midseason turnaround, Wheeler allowed a career-high 12 hits in the loss at SunTrust Park. Four of those came during a two-run, first-inning rally, which would have been worse had Wheeler not frozen Charlie Culberson to strand the bases loaded. But the Braves did not stop their assault on Wheeler, scoring again on Freddie Freeman’s RBI single in the second inning, Ronald Acuna Jr.’s solo homer in the fourth and Ender Inciarte’s run-scoring double in the fifth.

“You’re going out there throwing 20 pitches an inning when it’s 100 degrees, you’re going to be a little tired,” Wheeler said. “But it’s no excuse. I missed spots and they made me pay for it. I just didn’t have it tonight.”

The Mets’ only run against Braves starter Max Fried came home in the second, when McNeil drove in Juan Lagares with a single. Acuna squelched another chance in the sixth, firing a 99.1-mph throw to cut down Todd Frazier at home plate. That proved even more significant two innings later, when the Mets rallied for two runs to provide the final margin.

“We had a chance,” manager Mickey Callaway said.

For the Mets, the loss was hardly the sort of blow to chase away their NL Wild Card dreams, though they did fall two games behind the Cardinals for the second Wild Card spot. But it did ratchet up the degree of difficulty of a late charge up the division standings -- a goal that Pete Alonso recently noted the Mets believe they can achieve. With August in full bloom (remember that 94-degree temperature at first pitch?), the Braves now hold a nine-game lead over the Mets. Only one of the more significant runs in Major League history would allow the Mets to overtake the Braves in the NL East.

Perhaps more pertinent is the fact that if the Mets want to win 90 games, a plateau that historically tends to ensure playoff admission, they’ll need to win almost exactly two out of every three the rest of the way. They may also need to do some of it without McNeil, who is due to undergo an MRI on Wednesday.

It’s a challenge, to be certain. The Mets feel they’re up for it.

“The thing I’m looking at is, do we ever give up?” Callaway said. “We didn’t give up tonight. We made it interesting. We made them use some relievers they probably didn’t want to use, which helps us out for [Wednesday]. Our guys haven’t given up.”