The Mets heard a sound mainly foreign in 2022 at Citi Field on Tuesday night. Boos. They were not thunderous, but they also were not voiced once or twice. It was part of the soundtrack of yet another frustrating loss against a not-very-good opponent.

This was supposed to be the easy part of the schedule, the part during which the Mets attached a strong finish to a mainly upbeat first five months of the 2022 campaign. The part in which the fans reveled in the countdown toward a first NL East title since 2015.

Instead, the Mets are wobbling, like a tired marathoner feeling for a finish line that is still not a step or two away.

“September is an eternity when you are trying to finish off a good season,” Buck Showalter said.

The Mets manager said that as he retreated to his office Tuesday night after discussing a second straight loss to the Cubs, this one 4-1, during his postgame press conference. Showalter talked a lot about near misses and things that could have been.

The Mets had the potential to open a lead in the first inning. But Brandon Nimmo was called out when he was hit by what would likely have been a clean Jeff McNeil ground single, and Pete Alonso missed a two-run homer by inches when he said the wind blew his launch just to the foul side of the left-field foul pole. By the time Alonso hit his 34th homer, it was the ninth inning and the blast was cosmetic — much like the ninth-inning homer that Francisco Lindor drilled the previous night in a 5-2 Cubs triumph.