Phillies catcher J.T. Realmuto, left, is unable to make a...

Phillies catcher J.T. Realmuto, left, is unable to make a play at home plate as Mets' Juan Lagares slides safely during the 11th inning on Monday, April 15, 2019, in Philadelphia.  Credit: AP/Derik Hamilton

PHILADELPHIA — If Monday night was a representative preview of what the Mets-Phillies season series will be like — and more significantly, what the NL East competition is going to be like — then make sure to rest up when you can and have plenty of snacks ready.

The Mets beat the Phillies, 7-6, in an 11-inning game that took 4 hours, 29 minutes. And despite getting a tad defensive at all of the questions about his bullpen management and other decisions, Mickey Callaway was pleased that his first-place Mets (10-6) ended up with a win.

“We got away with some stuff,” Callaway said. “We walked a pitcher and gave up a few runs. We popped up off the bag and put ourselves in a bind there. We walked three guys and walked a run in. But we still came out with a win, and that says a lot.”

Rhys Hoskins gifted the Mets the winning run when Michael Conforto’s grounder to first deflected off his glove to second baseman Cesar Hernandez, who threw it into the ground. Juan Lagares scored from second on Hoskins’ error.

Callaway refrained from using his best reliever, closer Edwin Diaz, in several critical moments, including the eighth, when Jeurys Familia and Robert Gsellman combined to walk in the tying run. That wound up working out when Diaz handled the bottom of the 11th, striking out Bryce Harper, Hoskins and J.T. Realmuto to end it.

Saving Diaz for that specific spot resulted in Callaway revealing three rules for using Diaz:

*** Diaz will not pitch more than an inning, at least not before the playoffs. General manager Brodie Van Wagenen said Mets decision-makers came to this conclusion based on Diaz’s performance last year, though it’s not clear how much input Diaz had. This is a significant departure from Callaway’s philosophy last season, when he brought Familia into a save situation in the eighth inning three times by April 16.

“As we manage [Diaz’s] workload early in the year, that’s going to be how we put all of us in a position to succeed,” Van Wagenen said.

“We don’t work in absolutes in terms of identifying when players are going to pitch solely or exclusively, but at the same point, we have a plan and we’re going to try to stick to it as best we can.”

Said Callaway: “This year is different. We have different personnel.”

Diaz said: “[Callaway is] the manager. I would do whatever he wants. I will be ready every time when they need me. If they want to pitch me three or more outs, I’ll be ready. If they want to pitch me one inning, I’ll be ready.”

*** Diaz will not pitch before the ninth, even if it’s the game’s biggest spot. “We could have brought Diaz in for one out and then not had anybody to save the game,” Callaway said.

*** Diaz will not pitch in a tie game on the road. Callaway said he was ready to bring in Drew Gagnon, a 28-year-old called up from Triple-A Syracuse hours before the game, to face Philadelphia’s best hitters if the Mets had not taken the lead in the top of the 11th. Diaz will be saved for save situations. “It’s just something I feel strongly about,” Callaway said.

The late drama turned everything else into a footnote.

Jeff McNeil (3-for-5, .404) switched from leftfield to third base midgame, then made two diving plays that “probably saved us the game,” Callaway said. Fifteen of 16 starting position players had at last one hit. Noah Syndergaard (five innings, five runs) and Aaron Nola (four innings, five runs) matched up in a potential pitchers’ duel that never was.

The 25-mph winds blowing out to rightfield meant a steady stream of garbage strewn about the field, capturing well the essence of a game that should not be described as crisply played.

“This was a great win tonight,” Callaway said. “The guys played a heck of a game. You know what, we battled through it, we grinded through it and it was a great win. It was great to see.”

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