NEW YORK — This idea the Cubs will simply get healthy, get hot and take off assumes all the other parts will stay in place, that there will be no more injuries, downturns or surprises when this game is constantly shifting in real time. No one knows what the crisis of confidence might look or feel like the longer this goes and the deeper the defending World Series champs get into the season.

This team is in survival mode now. How will everything start clicking when the Cubs don’t know what they’re going to get from one night to the next?

“We’ve earned the right to be in this position,” manager Joe Maddon said after watching a bullpen meltdown during Wednesday night’s 9-4 loss to the New York Mets. “We’ve played well enough to be a .500 club. We have a nice group. And I believe in our group. But we have to prove it on the field.”

The Cubs got back-to-back homers from Anthony Rizzo and Ian Happ leading off the game, saw Kyle Schwarber launch a 467-foot rocket over the Citi Field bridge and knocked out Matt Harvey after four innings, but still couldn’t manufacture any tack-on runs.

Redeploying Mike Montgomery weakens a bullpen already stressed from covering for a rotation with a 4.66 ERA and 24 quality starts. The Cubs didn’t back up the lefty swingman in the second inning when All-Star third baseman Kris Bryant fielded a routine groundball and then dropped the third out, creating an unearned run.

But it’s not the errors as much as the plays not made by what was supposed to be an elite defensive unit. Montgomery couldn’t put away Steven Matz — a pinch-hitting pitcher — in the fourth inning and that bases-loaded infield single helped set up two more runs.

“We need to do a better job,” Rizzo said. “We got to hold leads. We got to hit better with runners in scoring position. We got to give our pitchers better opportunities to come in with a bigger lead. All the little things — you got to get back to it.”

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Around the Cubs, there is a flip side to any optimistic regressions to the mean with their young hitters. Like Carl Edwards Jr. not being almost perfect. After throwing seven pitches in a scoreless seventh inning, Edwards watched Chicago guy Curtis Granderson lead off the eighth by driving a curveball into the right-field seats for his 300th career home run and a 5-4 lead. A disappointing Mets team (30-34) piled on against Edwards and Hector Rondon.

Besides drawing from the playoff experience and relying on exceptional individual talents, what can this team bank on at the moment? The Cubs are 32-33, have trailed in 51 games so far and haven’t won three series in a row since April.

“There is a certain unpredictability about us,” Maddon said. “That’s why we’re a .500 ballclub right now. That’s what happens when you’re .500. You don’t play that same good game every day.”

It can’t all be written off as youth, as much as Maddon will spin in that direction.

“Happ didn’t play in the big leagues last year,” Maddon said. “(Willson) Contreras played half a season. Schwarber did not play at all. (Javier) Baez was a backup player. And (Albert) Almora came up in the middle of the season.

“I love my names as much as everybody else does. But these are really young and inexperienced guys. What you’re primarily seeing is young guys battling to get back to what we had been last year without the benefit of having veteran experience.”

Having said all that, the National League Central is a bad division with only one team barely above .500 — the Milwaukee Brewers in what was supposed to be a rebuilding year.

“We’re still a confident ballclub,” Schwarber said. “We’re going to go out there every day and we’re going to compete our asses off.

“I’d take our guys any day.”