NHL

Kid Kreider making an impact for Rangers

What were you doing two weeks past your 21st birthday, on the doorstep of summer? Bumming at the beach? Taking full advantage of using your own ID at your neighborhood beer distributor? Lifeguarding? Working long hours for short pay at some internship on Wall Street?

All of the above?

Chris Kreider, he’s got other ways to occupy his time at a moment when most of the kids his age are majoring in knucklehead. He’s trying to win a Stanley Cup, finally, at long last, after a whole month in the NHL, trying procure a ring to add to the NCAA championship he won at Boston College last month.

Hey, we all need hobbies at that age, right?

“This isn’t easy,” he said last night, sitting in front of his locker, talking in a voice softer than a whisper after contributing a goal and an assist to the Rangers 3-0 opening-game win over the Devils in these Eastern Conference Finals. “This is pro hockey, you know?”

No, it isn’t easy, even for Kreider, making the kind of immediate impact on a championship-level team we haven’t seen around here since another 21-year-old kid named Jeter hit the ground running in the Bronx 16 years ago. But even Jeter, that slacker, spent a couple of years in the minor leagues getting ready for the main stage. Even Jeter, that loafer, spent a whole baseball season – plus a cup of coffee or two to boot – preparing for his postseason solo.

Kreider? He walked right out of college and into the NHL playoffs, onto a team with a worker’s pedigree and championship aspirations. And here’s the best part: he hasn’t been full phenom. He’s been human. He had some early success. And then some early failure.

His coach, John Tortorella, isn’t the kind to swoon easy, isn’t exactly a coddler, and so he showed the kid that even prodigies sometimes pay consequences, limiting Kreider’s playing time following a couple of defensive gaffes that helped the Rangers lose Game 4 of the Capitals series.

“He’s played well,” Tortorella said. “But he’s learning.”

If you think it’s impossible for professional sports to be this easy … well, take a look at Kreider at the conclusion of these games. Look at how he falls onto his stool, how tired his eyes are, how completely spent he is. It [ital] isn’t [ital] easy. The exhaustion has nothing to do with a 21-year-old body in peak condition. It’s all about trying to keep up. Trying to fit in.

For you, for me, at 21 that probably meant getting the lunch order straight when the boys in the office sent you to the deli.

For Kreider, it means having to inject a youthful burst into a title contender without adding the youthful indiscretions that often go along with it. He paid for them with ice time late in the Caps series. Then paid the debt forward last night, setting up the ice-breaking goal and scoring the insurance one.

“The last thing I want to do is settle in,” Kreider said as the crush of notebooks and klieg lights enveloped his stall. “I don’t want to get complacent especially at this level. If I get complacent, the next thing you know I’m minus-2 and giving [Alex] Ovechlin a one-timer in the slot (his felony in the Washington series). I have to stay extremely focused.”

He has. His mistakes have been byproducts of being green, not careless. The day he signed his contract with the Rangers last month, another former BC Eagle, Brian Boyle, insisted: “If he comes, we’ll make him feel at home, we’ll welcome him with open arms.”

And they’ve been true to that.

“It’s awesome,” said Ryan McDonagh, the early hero last night who twice stymied potential New Jersey breakaways. “We just told him to keep moving his feet and keep moving his legs.”

“He’s been responsible away from the puck,” Tortorella said, “and he’s been consistently understanding how we have to play.”

Hell of an internship. Hell of a way to spend your summer. Hell of a time to be 21 years old, the whole career in front of you, starting with this splendid quest for a Cup. After a whole month. What took him so long?

michael.vaccaro@nypost.com