As far as first impressions go, Ronny Mauricio made a good one.

In front of a fan base starved for some positivity in the midst of a brutally disappointing season, Mauricio came up from Triple-A Syracuse and immediately made an impact, going 5-for-11 with two stolen bases and a 1.000 OPS.

And it came against a Mariners team that entered the series as one of the hottest in baseball and in first place of the tough AL West.

But as some of Mauricio’s fellow rookies — and former minor league teammates — have shown, a quick start to a major league career doesn’t necessarily equate to long-term success.

Brett Baty, for example, had to be sent back to Syracuse after a particularly rough stretch both at the plate and at third base.

And Mark Vientos has been inconsistent offensively and still doesn’t have a natural home on defense.

Then there’s Francisco Alvarez, as hot as any hitter in the league for much of the first half following his April call-up, who’s now 9-for-73 with one extra-base hit and 20 strikeouts in his last 84 plate appearances, good for just a .375 OPS.

Still, there’s no denying Mauricio’s talent and athleticism, especially as he’s shifted from shortstop to second base, with the Mets saying he’s going to test that versatility in the majors this season.

The 22-year-old played four different positions on defense at Syracuse this year.

After starting the season as the everyday shortstop, he shifted to second base and left field and also spent some time at third base.

In his first three games with the Mets, Mauricio started at second and played well, impressing both Buck Showalter and his new double-play partner, Francisco Lindor.

At 6-foot-3 Mauricio is tall for a second baseman, but Lindor is entrenched at short for the next decade and the Mets hope either Baty or Vientos can prove to be capable at third base.

Over the weekend, Showalter noted the importance of having versatility on defense, something Jeff Mcneil has provided over the last several years.

Unlike Mauricio, though, McNeil had experience playing multiple positions throughout his college career, so moving from second to third to the outfield in the majors wasn’t quite as much of an adjustment as it figures to be for Mauricio.

“It’s a little bit different for everybody,” McNeil said of getting comfortable playing multiple spots around the field in the majors. “I started doing it in college and was able to get a bunch of reps.”

According to McNeil, that could be the most significant challenge for Mauricio, who was signed by the Mets as an international free agent in 2017 and played nothing but shortstop until this year.

“You practice every single day in college,” said McNeil, who played second, short and the outfield both at Long Beach State and in the Cape Cod League before doing the same in the lower levels of the minor league system after being drafted by the Mets.

“It’s a lot different in pro ball,” McNeil said. “You don’t really practice, other than batting practice. There’s no everyday drills to work on and get better. I got lucky. When I got to the minors, I was already familiar with playing second and third. When I got to the big leagues, I still had to relearn some of it and it’s not easy. It takes baseball instincts.”

McNeil watched Mauricio at second since he’s been in Queens and said he “adjusted well there. I haven’t seen him play a lot, but he’ll get more opportunities and we’ll see how it goes.”

Mauricio has worked with infield coach Joey Cora extensively before games at second base, which has helped with the transition, but there’s no replicating game action.

“You have to get out there before batting practice, but even then, the game moves a lot quicker,” McNeil said. “The speed of the game is different. He’s an athletic kid. He can do it.”

The Mets are counting on it.