A.J. Ewing showed again Sunday why the Mets were aggressive in calling him up from the minors when they needed a center fielder earlier this year.

The 21-year-old helped lead them to an 8-1 win over Atlanta at Citi Field, coming up just a triple shy of the cycle.

Ewing has consistently impressed with his speed and defense, but his offense has been choppy, and he began Sunday with just one hit in his prior 11 at-bats.

But against Atlanta, he delivered an opposite-field double in a four-run first inning, hit a single to center in the third and then a homer to right in the fifth.

Carlos Mendoza called Ewing’s performance at the plate versus tough Atlanta right-hander Bryce Elder “impressive.”

“I just want to be myself and stay as simple as possible,’’ Ewing said.

“It shows how he handles stuff, especially after a couple of tough games,’’ the manager said.

Mendoza likened Ewing to fellow rookie outfielder Carson Benge in that both have been able to maintain level heads despite going through the ups and downs of their first season in the majors.

“Similar to Carson, you can’t tell if he went 0-fer or had a good game,’’ Mendoza said. “It’s his ability to stay consistent. He’s gonna use the whole field. He hit a homer to the pull side, play defense and run the bases. He’s a mature guy and is learning, adjusting and developing at the big league level.”

---

In the never-ending game of musical chairs that is the Mets rotation, Tobias Myers is scheduled to start Monday’s series opener against the Reds in Cincinnati, Mendoza said.

Myers has been at Triple-A Syracuse, where he pitched 2 ²/₃ innings and threw 36 pitches Thursday.

Despite the somewhat limited action, Mendoza said Myers could be stretched out a bit.

“He’s gonna go,’’ Mendoza said when asked if Myers would be used just as an opener. “We’ll see how the game unfolds. We’ve got a pitch count in mind.”

After that, Mendoza said the Mets would figure out the next two games in Cincinnati, although Christian Scott and Nolan McLean are lined up for them.

Myers, acquired along with Freddy Peralta from Milwaukee in the offseason, hasn’t pitched more than two innings in a game in the majors since going 2 ²/₃ on May 2.

President of baseball operations David Stearns said Friday that Myers’ “role is going to be whatever we actually need at that point. … He could pitch at the front of games, it could be more in the swing capacity that we saw at points this year.’’

---

Coming off an ugly start in his previous outing, Peralta allowed three hits to open Sunday’s game, as the Braves pounced on his four-seam fastball.

So Peralta and catcher Luis Torrens shifted, and he used his four-seamer less, and his curveball, slider and sweeper more.

It helped Peralta get through five innings, although he needed 90 pitches to do so.

“I was able to make pitches when I needed to,’’ Peralta said. “I was looking forward to [pitching] at least six, but some things happened.”