Mets’ free pass problem coming at a heavy cost

That the Mets lost Tuesday was not a surprise. It was only surprising that the Phillies did not win by more than 4-0.

After all, the Mets managed just four hits and did not even move a runner to scoring position until the ninth inning. Their pitchers issued another eight walks, authored a bases-loaded hit by pitch for the second straight game and added two wild pitches while the defense botched a rundown.

The Mets exist on a razor-thin realm between being July sellers en route to 70-something wins or trade-deadline buyers, 80-something victories and wild-card contention. It fluctuates on a thin margin of error — and too often the Mets have veered toward error, like Tuesday afternoon when they did not even allow a stolen base, which has been a particular bugaboo this season.

Instead, their No. 1 self-inflicted nemesis — issuing bases on balls — led not only to their 14th loss in their last 21 games, but a chain of events that will force them to an emergency starter in Philadelphia on Wednesday.

“We have to be perfect,” Carlos Mendoza told The Post. “We can’t be giving free bases and extra outs. It feels like when we do that, we pay for it.”

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Edwin Diaz lost the strike zone and blew a two-run ninth-inning lead on Monday night and the Phillies won in 10 innings. And in a decisive third inning Tuesday, Jose Butto walked three and for the second straight game Alec Bohm was hit by a pitch with the bases loaded. The Phillies scored two runs in the inning on just one hit and, meaningfully, Butto threw 41 pitches.

That led to 97 pitches in all and Butto being out after five innings and having to over-involve a heavily used pen. Jake Diekman worsened matters when he walked three consecutive batters and could not complete the seventh inning. Mendoza had wanted to avoid using Sean Reid-Foley for a second straight day and a third time in four. But with just a 2-0 deficit, Reid-Foley was summoned for the ninth. But as Reid-Foley gave up four straight hits and two runs, Mendoza began to warm Adrian Houser , who worked hard enough in the pen that he no longer was a consideration to make his scheduled re-entry to the rotation on Wednesday even without appearing in the game. So, the plan was to summon Joey Lucchesi from Triple-A to make that start.

It was another reminder that the Mets are not going to run this summer unless they stop walking so much.

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The Mets are walking a MLB-high 11.8 percent of the batters they face. Pitching coach Jeremy Hefner cited it as an issue that needed to be remedied when on “The Show with Joel Sherman and Jon Heyman” podcast two weeks ago. Mendoza echoed that Tuesday.

“It is one of those things that since Day 1, we have been addressing and preaching — to stay on the attack, get strike one, get to two strikes,” he said. “And we haven’t been able to do that, so we have to keep working.”

The lack of control creates an avalanche of problems. It shortens starts. It forces the use of more relievers. It blunts a .222 batting average against, which was fifth best in the majors. It puts more runners on against a team that has allowed a MLB-high 56 steals (11 more than any other team) while nabbing just four. It puts runners on against a team that was 28th in Defensive Runs Saved with a negative result at every position except right field. It puts runners on when the Mets staff is sixth in hitting batters and seventh in throwing wild pitches.

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It is just too many free bases and increased stress for the pitching at a time when the offense still has not found its best version — if it ever will.

“We are better than this and we will get there [to a better place] because we have good players,” Mendoza said.

But it is a quarter of a season now and the Mets are 19-22 — three games under .500 for the first time since they began to dig out from a 0-5 start to the year. They are now 1-4 in what always loomed as a treacherous seven-game run against the NL East titans Atlanta and Philadelphia.

They know Kodai Senga is not close to a return after shutting down his rehab from a shoulder ailment to try to better align his mechanics. Diaz is still working back from a lost 2023 and hardly resembles his dominant 2022. And the offense has names, but not game right now. Mendoza did not start the struggling Jeff McNeil on Tuesday. McNeil is part of a lefty brigade with switch-hitter Francisco Lindor, Brett Baty and, when they play, Omar Narvaez and Joey Wendle, who are just offering too little, in general, and specifically delivering too little damage against righty pitching. Wendle is going to be designated for assignment to get Mark Vientos up, so the Mets do not have to use as many lefties against southpaw starters, as well.

Phillies righty Aaron Nola was perfect for five innings en route to a complete game that gave Philadelphia’s pen the kind of reprieve that the Mets so desperately needed.

Instead, the walk-a-thon continued at Citi Field and the Mets currently have a free pass in the wrong direction.

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