Dallas Stars Defenseman Miro Heiskanen may be understated, but his play speaks for him with all the force, dynamism and range of a concert choir.

During these playoffs, he has some of the most prominent voices in hockey singing his praises.

Heiskanen, a 21-year-old Finn, is in his second N.H.L. season and his first Stanley Cup finals, having led the surprising Stars to their matchup against Tampa Bay with contributions up and down the 200-foot length of the ice. His impact in Dallas’s defensive structure and transition game has been immeasurable. But his 25 points in 25 games can be quantified easily: He leads the team and has accrued more points than any other defenseman this postseason. That represents a leap from the regular season, in which he posted 35 points in 68 games.

“You’re very impressed seeing how quickly he’s developed into one of the top D in the league; there’s no question about it,” said Victor Hedman, the Lightning’s top defenseman and a Conn Smythe Trophy candidate as the second-highest scoring defenseman this postseason.

In Game 4, Heiskanen set up two one-timers in the third period, including one for Alexander Radulov where the pass traveled diagonally across most of the offensive zone, and he played a vital role in the tying goal. His well-timed pinch sustained an attack that culminated in Joe Pavelski’s equalizer, which he assisted. He also had one of the most dangerous chances in overtime, a rising shot to the top left corner. But Tampa Bay scored on a power play to win, 5-4, and take a three games to one lead in the series after a penalty to Jamie Benn that the Stars considered questionable.

Heiskanen’s jump in scoring has spearheaded a Stars offense that was the focus of the unexpected second training camp this season. These finals started more than a year after the 2019-20 preseason began, and the Stars used the pause in the season forced by the coronavirus pandemic to shuffle their lines and add strategies to bolster an offense that scored the fewest goals during the regular season among the 24 postseason qualifiers. Heiskanen, who shoots left-handed and can play on either side of the ice, said his own approach had not been affected by the changes.

“I just try to play a similar game every night,” Heiskanen said before the start of the finals. “Of course the whole team is playing really good right now, so that helps me a lot, too. But yeah, I just try to play the same way every night and try to help my team every night.”

Rick Bowness, a veteran coach who has been behind the bench in five different decades, was more effusive about Heiskanen’s utility and versatility. Bowness marveled at Heiskanen’s hockey sense and his ability to process new information quickly and comprehensively. He also described Heiskanen as an “elite athlete” but was equally impressed by his drive to succeed.

“If you need a big play, he makes it,” said Bowness, who later responded to a question about what Heiskanen does for his team by saying, “Everything.”

He added: “He wants to be on the ice. He wants the ball. He wants to be able to carry his team on his back. You’ve got to love how much of a competitor he is on top of being an elite player.”

While defense has historically been a position that required considerable development time, young blue liners have emerged as prime performers in these playoffs. Colorado’s Cale Makar set a postseason record for points by a rookie defenseman with 15. But Makar’s record stood for only one day before Vancouver’s Quinn Hughes surpassed him with 16 points.

Heiskanen has drawn few direct comparisons, with many instead describing him as a composite of some of the greatest defensemen. The seven-time Norris Trophy winner Nicklas Lidstrom recently compared Heiskanen with the standard-bearer for offensive defensemen, the Hall of Famer Paul Coffey, in terms of his speed, acceleration and effortless skating ability, as well as his penchant for beating opponents without stick handling.

“It looks like he’s played a lot more years in the league than he really has,” Lidstrom said. “You usually need a few years of making mistakes to understand how to be better at decision making. His game is already there and that is what impresses me.”

Jere Lehtinen, a former Dallas wing and a three-time Selke Trophy winner, saw Heiskanen up close as the general manager of the Finnish national team and compared his instincts, reads and ability to control the game to those of Lidstrom. Lehtinen said that Heiskanen had an ability to skate into plays similar to that of Scott Niedermayer, who won four Stanley Cups and molded an archetype for the roving No. 1 defensemen of successive generations.

Lehtinen said that Heiskanen would similarly “leave a mark” and potentially be a player to whom great defensemen are compared in the future. All that was left was filling out his physique, which Lehtinen said would make Heiskanen “unstoppable.”

Few have benefited more from Heiskanen’s well-rounded and consistent play than Dallas goalie Anton Khudobin. At 34, he has become a starter for the first time as Ben Bishop has missed most of the postseason because of an injury.

“I haven’t seen a player in 10 years like this,” Khudobin said. “Great skater. He can play simple, and at the same time, he can be creative.”

Heiskanen starred in Finland, first at the top junior level and then at the senior level. In his first senior season, Lehtinen said, Heiskanen “jumped out every game,” and in his second year he won the top league’s award for its best defenseman.

An injury before the Stars’ training camp factored into the team’s decision to loan him to his Finnish club for that second campaign, in 2018. That also allowed him to participate in all three of hockey’s top international tournaments: the world junior championships, the world championships and the Olympic Games.

Those high-stakes games helped season Heiskanen for the playoff stage, where his ranginess has been on full display. Heiskanen changes gears fluidly and awaits the right moment to unleash his top velocity.

“He manages his speed effectively up the ice,” Lehtinen said. “He can join the rush and still be the first guy back in his own end.”

In Game 2 of the conference quarterfinals against Calgary, he performed the inverse action, breaking up a play in the center of the right face-off circle in the defensive zone and then dashing ahead of all nine skaters on the ice to finish the play with an uncontested breakaway goal. In that same game, he used his mental attributes rather than his physical ones to score a second goal, a sneaky heave along the ice from a sharp angle that stunned goalie Cam Talbot to the point where he could not hide his surprise.

In the clinching Game 6 of that series, the Stars faced a 3-0 deficit. Heiskanen scored the first of Dallas’s seven consecutive goals, an act Bowness described as “putting the team on his back.”

Even in Game 3 of the finals — which Dallas lost, 5-2 — he rebounded from an early mishap during which he lost an edge on his skate, fell and turned the puck over for a Nikita Kucherov goal. In the second period, his knack for zone entries on the power play was on full display — he nearly put home a rebound after orchestrating a successful one — and in the third, he scored a goal that breathed life into the sluggish Stars.

So far in his career, Heiskanen’s profile has been remarkably low. He was not a finalist for rookie of the year last season, despite being Dallas’s lone All-Star. This season, he finished 12th in the Norris Trophy voting, tied with the Rangers’ Tony DeAngelo.

“Everyone you talk to on the opposition, when you talk to other coaches after games — ‘Wow, that kid can fly; that kid does this, he does that.’” Bowness said. “Yeah, we see it every night. When he’s that low in the rankings, that just tells me that not enough people are watching our team closely. It’s as simple as that.”

Such snubs seem unlikely to affect Heiskanen, even less so as he pursues the Conn Smythe Trophy as the postseason’s most valuable player and the unparalleled thrill of hoisting the Stanley Cup.