Mets relief pitcher Seth Lugo leaves after being relieved during...

Mets relief pitcher Seth Lugo leaves after being relieved during the eighth inning against the Cubs Sunday in Chicago. Credit: AP / Matt Marton

CHICAGO — Of the Mets’ 17 blown saves this season, the most in the majors, this one might have caused the most tension.

The Mets lost to the Cubs, 5-3, on Sunday after Javier Baez’s game-changing, day-ruining three-run home run in the bottom of the eighth against Seth Lugo, whose presence in the game at that point exemplified the flaws with the Mets’ bullpen.

After a testy postgame news conference, manager Mickey Callaway began to shout expletives at this reporter, which got the attention of Jason Vargas, who had to be restrained by teammates.

The Mets issued a statement apologizing for the incident.  “We do not condone this type of behavior from any employee,” the statement read.

The loss meant the Mets (37-41) split the four-game series at Wrigley Field. They haven’t won a road series since April 1-3 in Miami and haven’t managed even a three-game winning streak in a month.

“It always feels like a missed opportunity,” Callaway said, “when you’re leading and don’t get it done.”

Heading into the late innings after Jacob deGrom allowed two runs in six innings, Callaway turned first to Lugo, who had Saturday off after tossing two innings Friday. That has been standard procedure for the Mets’ most effective reliever, whom they are hesitant to use on consecutive days because of the way his arm recovers.

Lugo was something less than his dominant self, allowing one hit and throwing 19 pitches — several of them well out of the strike zone — in the seventh. Callaway stuck with him for the eighth, and after Lugo walked Anthony Rizzo to put two on with one out, pitching coach Phil Regan visited the mound.

Baez blasted Lugo’s 42nd pitch deep to right to put the Cubs ahead. Callaway then pulled Lugo, who has a 2.87 ERA after allowing his first runs since May 19 (11 1⁄3 innings).  “I thought he had good stuff,” he said. “Just didn’t execute one pitch.”

Said Lugo, “I wasn’t executing any pitch. I don’t think anything was there. I threw probably two or three pitches I was happy with out of [42]. The stuff just wasn’t there today.”

Throughout, closer Edwin Diaz remained in the bullpen. The Mets say they will use him for a maximum of four outs — pushed up from three to begin the year — and Callaway was adamant that attempting to get five outs from Diaz is not an option. “We’re not going to use him for five outs,” he said. “I know you guys keep on asking, but my answer is going to stay the same.”

Diaz, who had appeared in one game in the previous week, throwing 12 pitches on Friday, didn’t warm up.  “I didn’t get the call to start warming up at any moment,'' he said. "I was ready if they wanted me, but I’m sure he has reasons why.”

Callaway became agitated with the line of bullpen-management questioning. Asked if the Mets’ Diaz plan should be flexible, he said: “Just because you [another reporter] think so? Absolutely not. We have a very good plan. We know what we’re doing. We’re going to stick to it.”

The Mets’ 5.30 bullpen ERA is a bottom-five mark in baseball. It’s worth noting that the Mets’ season-opening bullpen picture included free-agent additions Jeurys Familia and Justin Wilson, who have been injured and/or ineffective this year, severely limiting Callaway’s late-game options.

The late bullpen mess ruined what had been a good day for the Mets. Pete Alonso — whose 27th homer broke the Mets’ rookie record — and Tomas Nido went deep against Cole Hamels (seven innings).

“We put ourselves in a position to win three out of four,” Callaway said. “We came five outs away. We just didn’t get the job done.”

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