Steven Matz delivers a pitch against the Arizona Diamondbacks at...

Steven Matz delivers a pitch against the Arizona Diamondbacks at Citi Field on Saturday, May 19, 2018. Credit: Kathleen Malone-Van Dyke

Job No. 1 for Steven Matz is staying healthy. Job No. 2, according to Mickey Callaway, is controlling his emotions on the mound when something goes wrong.

The manager/ex-pitching coach/new age self-help guru said before Saturday night’s 5-4 Mets win over Arizona that Matz has to “make sure he doesn’t get affected by bad calls or a missed play.”

Callaway must have been peering into his crystal ball, because Matz may have been negatively affected by a ball-strike call, a missed play and a questionable replay review in Arizona’s three-run fourth inning.

Matz, who left trailing 4-2, got a no-decision when Devin Mesoraco tied the score with a two-run homer in the eighth. The Mets went home happy, thanks to Wilmer Flores’ walk-off sacrifice fly in the ninth.

But questions about Matz lingered after he lasted only four innings (79 pitches) and got another quick hook from Callaway.

“I think it comes down to me — I’ve got to show the manager that I can go out there and dominate,” Matz said. “He made the right decision. We won the game.”

The Mets were leading 2-1 when Paul Goldschmidt began the fateful fourth with a homer to left.

Two outs later, Matz went to 3-and-2 on Jarrod Dyson before walking the speedy (and .183-hitting) outfielder on an outside pitch. Except Matz didn’t think it was outside. He hopped on the mound and snatched at the return throw from Mesoraco.

“I think that guys are obviously going to be emotional at times,” Callaway said. “What I did see after he snatched the ball or whatever, he went through that routine to reset himself, and that’s what we’re paying attention to the most.”

For what it’s worth, the “heat map” on MLB.com’s Gameday showed the pitch was outside. Matz called it “borderline” but added: “A two-out walk to a lefty there is unacceptable.”

That’s not what Callaway was most steamed about. It was what happened next.

“I didn’t think he let stuff bother him,” Callaway said. “But he’s got to do better against the eight-hole hitter when the pitcher’s on deck . . . If you’re a starting pitcher, you have to be able to get the eight-hole hitter out and be able to pitch around him when that calls for it.”

The eight-hole hitter was former Yankees catcher John Ryan Murphy, who had an RBI single in the second. Murphy was batting ahead of pitcher Patrick Corbin, who is actually a good hitter but who is a lefthanded batter.

Dyson was caught off first by Matz, who made a pickoff throw as Dyson was heading to second. Flores threw to second in an attempt to end the inning. But Flores’ throw went to the third-base side of second and Dyson was called safe.

Callaway challenged the call. Dyson appeared to be out on replay — especially to Mets fans in the ballpark — but after a replay review of 2:04, the call stood and the Murphy at-bat continued.

Dyson stole third as the Mets decided not to have Jose Reyes cover. Matz, who was ahead of Murphy 1-and-2, saw the count go full. Then he threw an 83-mph changeup in the middle of the plate and Murphy sent a high drive through the fog and over the left-centerfield wall to give Arizona a 4-2 lead.

Matz slapped his pitching hand into his glove and yelled something every Long Islander would recognize. In the dugout, Callaway turned his back and muttered to himself. Pitch selection was the problem, Callaway later said.

“In my mind, you don’t throw changeups to pitch around guys,” Callaway said. “You throw your fastball because you can get it where you want to.”

Said Matz: “I’ve got the pitcher on deck and I just made a mistake. I can’t let that stuff happen.”

Matz struck out Corbin to end the inning. A few minutes later, his night was over. And even after the Mets’ dramatic win, questions about how Matz handles himself on the mound were just getting started again.

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