"He has very high standards for himself, he's a very driven guy. He's a very quiet, polite, humble person, but he knows how good he is," said Stars assistant coach Rick Bowness. "And there's no doubt in my mind that he will be even greater."
Heiskanen has a great pedigree. He was selected third overall in the 2017 NHL Entry Draft. In 2018, he won the Pekka Rautakallio Trophy as best defenseman in the Finnish Elite League. He was just 18 at the time.
That said, stepping up to the NHL is a big challenge. While everyone was impressed with Heiskanen's performance as a rookie last season, he ranked 45th in scoring among defensemen with 33 points (12 goals, 21 assists) in 82 games.
John Klingberg led the Stars with 45 points (10 goals, 35 assists) in 64 games. He was plus-6 on plus-minus, while Heiskanen was minus-14. Klingberg also was plus-73 in SAT (shot attempt differential at even strength), tops on the Stars. Heiskanen was plus-14. In the playoffs, Klingberg was plus-70 in SAT and Heiskanen was minus-40.
Now, that's putting a lot of weight on shot differential, but it's an area where top defensemen excel. San Jose's Brent Burns was plus-428 in SAT last season. Calgary's Mark Giordano was plus-371. They finished second and first in voting for the Norris Trophy. They also finished second (Girdano at 74 points) and first (Burns at 83 points) in scoring, so that tells you a little bit about what it takes to be considered the best defenseman in the world.
Which means Heiskanen has some work to do.
But if anyone is ready to work, it's the determined blueliner. Defensemen usually take several years to mature, and veterans are astounded by what Heiskanen has already accomplished.
Former Stars defenseman Ben Lovejoy was on NHL Network in August and said: "Miro Heiskanen is gonna win six Norris Trophies."
Lovejoy added: "He's honestly like nothing I've ever seen. He plays like Nick Lidstrom, but he skates like Connor McDavid, and he is just so cool, so collected, so fast. ... He has so much more fun than any other defenseman out there, and he's never cracked a smile. He's just the perfect defenseman for the modern NHL. It was just so fun to watch him play."
Video: Miro Heiskanen comes in at No. 17 on the list
Stars defenseman Gavin Bayreuther said he learns from Heiskanen: "I always tell people that Miro is five years younger than me, but he's so much better than me, so you have to watch him and learn from him."
That puts into perspective where Heiskanen already sits, and it also shows that reaching his goal is possible. But how does he go through the steps of improvement? Bowness has coached in more than 2,000 NHL games and said he believes a lot of his job is simply to set up an environment where Heiskanen's can grow.
"Sometimes, you just have to stay out of his way," Bowness said. "The worst thing you can do with a kid like Miro is overcoach him. He's got great instincts for the game, let those instincts take over."
Bowness said he and Heiskanen are having regular conversations during a game, as they use moments of play to hammer home good decision-making.
"You monitor him, it's more that," Bowness said when asked about "teaching" his young student. "He has very high hockey IQ. We talk a lot during the game, and I'll say, `Miro, did you see that?' And he gets it. We do a lot of coaching as the game unfolds in front of us. He doesn't need to see a lot of video. He's one of the few guys you coach who doesn't need to see a lot (of video). He sees the game in front of him."
And that might be the key going forward.
Heiskanen often says, "I play my game." And while that can be funny, because on the surface it really doesn't say much to the fans, it actually is pretty deep when you study it. Heiskanen's game is unique, and he is the one who is going to shape where it goes. Coaching will be important, but a lot of what Heiskanen becomes will be because of his own mind and how he reads the NHL. As he studies his teammates and opponents, his creativity will be sparked simply by playing more and more hockey.
As Bowness said, sometimes you do just have to stay out of his way.
In the year before he came to the Stars, Heiskanen played in the Finnish Elite League, the World Junior Championship, the Olympics and the IIHF World Championship. It was an exhausting stretch, but one he seemed to handle quite well. That said, when he had some down time this past summer, he was able to dedicate himself to some off-ice training. He packed on eight extra pounds of muscle and worked on his already-great skating.
And that, as much as anything, shows that he does indeed have plenty of room to improve.
"It was a great summer with my workout coach," he said. "I think I had a lot more time than usual. There was a lot of time to work. I got stronger, that was my biggest goal. … I got more acceleration."
Heiskanen is already known as one of the best skaters in the NHL, but said he feels he definitely can improve that area.
Video: Stars gear up for new season with big goals in mind
"Of course, I can be a better skater," he said. "I think I am a better skater now than what I was last year. I want to work at that and be better all of the time."
Montgomery added that there still are details to Heiskanen's game that can be refined.
"He's done most of the work already with his off-ice stuff. He's come back with eight pounds more muscle mass, which is going to help him log more ice time and win more battles," Montgomery said. "There are little things to his game, stick positioning, defending the rush. He's so good with his defensive stick causing turnovers that sometimes he relies on it too much and it takes away from his skating ability and being able to pivot and go."
The Stars last season used Heiskanen a great deal on the second pair with Roman Polak, and that will probably change this year. With the addition of Andrej Sekera and the familiarity of the coaching staff with the talents of the defensemen, Heiskanen could become a player who fits in a lot of different roles.
"We have a lot more flexibility back there and I think you're going to see a lot more movement in the pairings," Montgomery said. "It was pretty steady from the All-Star break on, who our top four was. I think there's going to be a lot of interchangeable parts, which as a staff, we like just because of matchups. You're playing a speed team, you might have different pairings than when you're playing a heavy team."
It also might matter who is playing well at the time and who can best benefit from a pairing with Heiskanen.
"If he needs to be out there with John (Klingberg) because we need a goal, then he's out there with John," Bowness said. "If he needs to be out there with Roman (Polak) because we're protecting a lead, then he's out there with Roman. He's going to play in all those situations. His partner, a lot of the times, is based on our needs at the time."
Heiskanen averaged just 1:40 in power-play time on ice per game last season and tallied eight power play points. Players like Burns and Giordano each averaged more than 3:15 in power play time on ice and each had more than 20 power play points. Those are also areas where Heiskanen has a ton of room for growth when you look at the top blueliners in the league.
All of this nit-picking might seem silly when you're talking about a second-year player who just turned 20 in July, but Heiskanen has a goal, and it will be intriguing to see how he and this team go about the process of making that goal a reality.
"I think his potential to be better is great," Montgomery said, embracing the absurdity of the question. "He's 19 years old, turning 20."
This story was not subject to the approval of the National Hockey League or Dallas Stars Hockey Club.
Mike Heika is a Senior Staff Writer for DallasStars.com and has covered the Stars since 1994. Follow him on Twitter @MikeHeika.