NEW YORK — For nearly two weeks, the New York Mets’ offense, besides one outburst, has been a problem. The alarming trend continued Monday night against the Atlanta Braves.

On a sweltering night at Citi Field, with the temperature at first pitch a balmy 87 degrees, the Mets’ bats remained frigid in a 3-2 loss. New York has dropped nine of 10 games and scored 19 total runs in those nine defeats. The exception was an 11-run effort fueled by seven home runs in the Mets’ win over the Philadelphia Phillies on Saturday.

What was a 5½-game lead in the National League East has suddenly morphed into a 1½-game deficit to the Phillies during the short span.

Mets manager Carlos Mendoza attributed the offense’s rough patch to two issues: Early deficits have produced poor at-bats, and the bottom half of the lineup has not been good enough.

“We’re relying so much on our top guys,” Mendoza said. “And we have a lot of guys in the bottom of the lineup that are going through it right now. And when that happens, once you get past the fourth or fifth batter, we’re having a hard time creating opportunities, creating chances for us, and it’s hard to score like that. We’ve been talking about, when we were playing well, how deep our lineup was. Now, we got a few guys that are struggling.”

The numbers support Mendoza’s assertion. Since June 11, the beginning of a stretch in which the Mets have been held to five or fewer runs in 12 of 13 games, New York’s 5 through 9 hitters have combined for the lowest batting average in the majors (.183) and the second-lowest OPS (.534). Only the Braves’ bottom five hitters have accumulated a lower OPS during the stretch.

On Monday, New York’s top three hitters — Francisco Lindor, Brandon Nimmo and Juan Soto — combined for four of the team’s six hits and its only walk. Brett Baty, the No. 9 hitter, notched the other two hits — singles in the third and fifth innings. The Mets’ 4 through 8 hitters went a combined 0-for-18 with five strikeouts.

“We need to continue to support the guys,” Mendoza said. “Continue to work. But it’s about results, right? So, yeah, we continue to have all the confidence in these guys, but we have to be better.”

Soto has not been a problem. After a relatively slow start to the season, which included questions about his hustle and relentless body language analysis, the star right fielder has been one of baseball’s best hitters in June with a .324 batting average, 1.188 OPS and 8 home runs in 21 games. On Monday, after the Mets fell behind 3-0 through three innings, he cracked a two-run home run in the sixth against Braves starter Spencer Schwellenbach, who logged seven innings against the Mets for the second time in a week, for New York’s only scoring putout.

But Soto failed to come through with runners on the corners and two outs in the eighth inning, striking out on a 3-2 slider from left-hander Dylan Lee below the strike zone on the eighth pitch of the at-bat. Lee then retired the side in order in the ninth inning for the game’s final three outs, sending the Mets to another defeat.

“He made a great pitch,” said Soto, who has 17 home runs with an .878 OPS this season. “He made really good pitches on the corners, and I just couldn’t come through on the last one. He threw a really good one. Just got me right there.”