Who could have known that firing the pitching coach and bullpen coach last week wouldn’t solve the Mets’ problems?

At least this one wasn’t a blown lead. The Mets’ lineup ensured that with a lackluster performance against Mike Soroka and three Braves relievers, but the comeback attempt wasn’t helped by the latest bullpen inferno.

In this one, Robert Gsellman surrendered three runs in the eighth inning to bury the Mets, who lost their sixth straight, 6-2 to the Braves at Citi Field.

“It is someone every night it seems, but it’s happened, we’ve got to control it,” manager Mickey Callaway said. “The one thing I’m focused on with our relievers is getting ahead. We have got to throw more strikes. Even when we get outs it takes a long time.”

Just over a week after the Mets fired pitching coach Dave Eiland and bullpen coach Chuck Hernandez, the late-inning madness remained at fever pitch. Johan Camargo’s three-run double against Gsellman in the eighth broke open a game the Braves came into that inning leading, 3-2.

The Mets, who fell 12 lengths behind the Braves in the NL East, got swept in four games at Philadelphia before this series, with the bullpen directly responsible for three of the losses. Most notably, closer Edwin Diaz surrendered five runs in the ninth inning Thursday for the loss.

On Friday, Jacob deGrom’s only real mistake was serving up a two-run homer to Austin Riley in the second inning, a blast from which the Mets never recovered. Overall, the right-hander lasted six innings and allowed three earned runs on six hits with seven strikeouts and two walks. It snapped a streak of seven straight starts in which the Mets’ ace allowed two runs or fewer.

“To lose that many in a row is frustrating,” said deGrom, who was the starting pitcher when this losing streak began last Sunday at Wrigley Field. “Us as pitchers have to do a better job to give those guys a chance.”

Before the game, during his weekly WFAN spot, Callaway said the Mets might need a “miracle” to salvage this season. Afterward, he backed away from the comment, saying it was a “play on words” given this weekend’s 50th anniversary celebration of the 1969 Miracle Mets.

“It doesn’t have to be a miracle, but we need to get it going,” Callaway said. “We have not put ourselves in a good spot. We do have a lot of games left, but if we don’t change what has been happening at some point, if it keeps going this way, heck, it will take a miracle.”

Tomas Nido’s RBI single in the seventh pulled the Mets within 3-2, but that was as close as they got. Neither Jeff McNeil nor Pete Alonso could deliver with two runners on base against Anthony Swarzak later in the seventh.

Alonso’s 28th homer of the season, a solo blast in the fourth against Soroka, pulled the Mets within 3-1. Already the holder of the franchise rookie home run record, Alonso still could catch Mark McGwire for another record. McGwire established a rookie record by hitting 33 homers before the All-Star break in 1987. Alonso still has seven games before the break.

Alonso attempted to deflect the blame for the Mets’ recent struggles away from the bullpen.

“Our job as an offense is to score runs, no matter the situation whether we’re up or down,” Alonso said. “Regardless of how the guys are pitching the job for us is to score more runs than the other team.”

The Braves extended their lead to 3-0 in the third, after Ronald Acuna Jr., singled leading off, stole second and went to third on a groundout. Josh Donaldson’s sacrifice fly brought in the run. Amed Rosario missed Nido’s throw for an error, which allowed Freddie Freeman to reach third after he had stolen second, but deGrom avoided further damage in the inning.

Riley smashed a two-run homer in the second that put the Mets in a 2-0 hole. It was the 13th homer in 41 games for the rookie. In the inning, Nick Markakis doubled leading off before Riley homered into the left-field seats.