HERNING, Denmark (AP) — It has been a busy year for Miro Heiskanen and it's not over yet.

The talented defenseman opened it at the junior world championship in Buffalo before becoming a mainstay on the Finnish men's national team at the next two top tournaments: the Pyeongchang Olympics and the ongoing world championship.

In that time the 18-year-old has established himself as a reliable defenseman who has passed the test against top NHL talents at the tournament in Denmark. He plays in the top unit, meaning he has to stop the offensive aces of the opposition and that's exactly what he has done.

NHL leading scorer Connor McDavid could attest to that.

On Saturday, Finland upset star-studded Canada captained by McDavid 5-1 and Heiskanen contributed a great deal.

He played 18:25 but his best moment came in the middle period when Canada was trailing 3-1 and desperately pressing to score. At one point, McDavid had just an empty net in front of him. Goaltender Harri Sateri was still at the far post and McDavid's shot from the left circle was heading for goal.

But then Heiskanen came seemingly out of no where to Finland's rescue, tipping the puck to safety.

"It was almost in the net but I hit the puck," Heiskanen said. "It was a good save."

When the two met in the third period, the result was a two plus two-minute penalty for high sticking for a frustrated McDavid, effectively ending Canada's chances of a comeback.

Finland captain Mikael Granlund praised Heiskanen.

"I have seen him at the games here and nothing really surprises me about him," Granlund said. "The way he skates, the way he handles the puck and sees the ice. He can play these games. He's been really, really good this tournament. He's got a great career ahead of him."

The obvious next step is the NHL.

The Dallas Stars picked him with the third overall selection in the 2017 NHL draft and signed him to a three-year entry level contract. He spent last season on loan with IFK Helsinki where he played since he was 17.

He finished with 23 points including 11 goals in the regular season and added three goals and nine points in the playoffs.

He said the transition has not been a problem.

"It was tough sometimes but mostly quite easy because I play with smarter players. Of course, the play is faster than at the junior category and I face stronger guys," he said.

The Denmark tournament proved he is ready to stop the best.

"It's nice to face those guys and see where I am," Heiskanen said. "It's a good test to play them, maybe I will play them next year in the NHL. I want to play there as soon as possible, that's my goal."

There's no doubt that he has the skills to make him a highly effective defenseman. But he knows he still has homework to do.

"I have to practice hard this summer and get little bit stronger," he said.

It's not clear when he might get the call from Dallas, though it's likely to be sooner rather than later.

In the meantime, he has to do what hockey rookies have to do: after practice with the Finnish national team, he can be found staying late on the ice and picking up pucks.