SEATTLE -- The Dallas Stars' 7-2 loss Sunday to the Seattle Kraken was further compounded by the loss of their star defenseman Miro Heiskanen in the second period.

Heiskanen was injured in the buildup to the Kraken's first goal with 17:50 remaining in the second period of Game 3. Seattle rookie forward Tye Kartye fired a shot on net from the left faceoff circle that may have been deflected before Heiskanen was struck in the face.

After the puck went off Heiskanen's face, he fell to the ground in front of the net before the Kraken's Jordan Eberle recovered the loose puck for a 1-0 lead. Heiskanen remained on the ice and clutched his face before receiving treatment from a member of the Stars' athletic training staff.

Heiskanen, who had a bloodied left cheek, went to the Stars' dressing room. Stars coach Pete DeBoer said there was no update on Heiskanen's condition and that the team will know more Monday ahead of Game 4 on Tuesday at Climate Pledge Arena with the Kraken holding a 2-1 series lead in this Western Conference second-round series.

"Obviously a big piece, but that's not why we lost," DeBoer said. "They were the better team tonight. No if, ands or buts about that."

Even if Heiskanen were to miss just one game, his departure would come with significant ramifications to the lineup. The 23-year-old defenseman is averaging 29:45 in ice time which is the most of any player in the postseason. Heiskanen, who also quarterbacks the first-team power-play unit and also plays on the penalty kill, is tied for third on the team with seven points.

Heiskanen played in all but two games for the Stars during the regular season. And when he was out of the lineup, the team turned to rookie Nils Lundkvist in his absence. Lundkvist, who was a health scratch Sunday, has yet to feature in the postseason.

As for what happened after Heiskanen departed?

Eberle's goal was the first of four unanswered goals the Kraken scored which eventually led to them taking a 5-1 lead into the final frame. The Kraken have had 16 different scorers this postseason and they relied on that versatility again Sunday. Alexander Wennberg, Carson Soucy, Matty Beniers and Eeli Tolvainen all scored in the second with Yanni Gourde and Justin Schultz adding two more in the third.

The Kraken had 11 players who finished the game with at least one point with Beniers, who was one of the three finalists for the Calder Memorial Trophy for the NHL's best rookie, leading the way with two points.

DeBoer pulled starting goaltender Jake Oettinger after two periods in favor of backup Scott Wedgewood. Oettinger finished with 12 saves on 17 shots. DeBoer was asked if he thought Oettinger had an off game.

"I thought our whole group was off," DeBoer said.

DeBoer was then asked what gave him cause for concern about that decisive second period.

"What didn't give me cause for concern tonight?" DeBoer chuckled. "We didn't stop the bleeding. We gave up all kinds of goals and opportunities. I wish it was one thing. I'll have to look at the tape. They were better in just about every area than us tonight."

Part of what allowed the Stars to advance to the second round and further legitimize their Stanley Cup aspirations is their defensive structure.

They entered Sunday ranked first in scoring chances allowed per 60 in 5-on-5 play, fourth in shots allowed per 60 in 5-on-5 play while also allowing the second-fewest high-danger scoring chances per 60 in 5-on-5 play, per Natural Stat Trick.

Dallas held firm in those categories. Seattle had 20 shots, 19 scoring chances and nine high-danger scoring chances in those 5-on-5 sequences. Those figures are all below the averages the Stars have allowed throughout the playoffs.

But it still didn't prevent them from having their poorest defensive performance of the postseason.

"I think we deserved what we got," Stars captain Jamie Benn said. "They were the hungrier team. They executed and took advantage of their opportunities."

This is not the first time the Stars have been in the position of falling behind in a series after giving up quite a few goals. In the first round, they fell into a 2-1 hole following a 5-1 loss to the Minnesota Wild before they closed out the series with three straight victories and only allowed three goals over the final three games.

Benn was critical yet measured when talking about the game. He was asked about how much Heiskanen's absence played a role in their second-period struggles and said that other players must step up in those situations.

"I think personally, I was probably one of our worst players," Benn said. "We'll fix it, we'll move on, have a quick memory and get ready for Game 4."