Heiskanen sustained a lower-body injury in the Stars' 5-4 win against the Wild on April 9.
He said at first he was nervous about the timing of the injury, especially because he had to miss the entire first-round series against the Colorado Avalanche last season because he was still recovering from knee surgery he had 2 1/2 months before the playoffs began.
"At the beginning you don't know what to expect or how long you'd be out, but it didn't feel too bad so that was a good thing," Heiskanen said. "When I knew it shouldn't be too serious, about a week to get back, it was nice to hear that because you don't want to miss any time."
It was great for his teammates to hear too because it reduced their angst.
"We knew the extent of the injury, and we knew he'd be back pretty quick, even if he missed Game 1 and Game 2," Stars forward Matt Duchene said.
Heiskanen didn't have to because he got the rest he needed by sitting out the last week of the regular season, missing Dallas' final three games. He returned to practice last Friday, the day before Game 1, got through it fine and then played a team-high 23:55 in Game 1.
"I've always said if you lose a defenseman of that caliber, it's like losing two top-six forwards, that's kind of the tradeoff," Duchene said. "So, I was hoping he'd be ready and he was. I'm sure he's feeling great now. It was good that he got through that first game and he was good and away you go, you don't even think about it."
That's exactly what has happened.
Heiskanen, despite playing 26:06 in Game 2 and then 43:05 in Game 3 -- with five blocked shots, two shots on goal and seven attempts, and the assist on Johnston's overtime goal -- is getting healthier as the series goes on.
He was happy to have two days between Games 3 and 4 to recover, including a full day off Thursday, but it doesn't even seem that was totally necessary for how he's feeling.
"It feels like it's getting better every day, and it feels good right now," Heiskanen said.
Stars coach Glen Gulutzan said he can visually see a difference in Heiskanen from Game 1 to Game 3 by how he's shooting and passing the puck, leading him to think the defenseman is at or as close as he can be to 100 percent health.
"There wasn't much velocity, plain and simple, when he first started out," Gulutzan said. "You could tell visibly he wasn't shooting the puck as hard or passing it as hard, but now you can't tell."
Even if he's not 100 percent, with Heiskanen it's hard to tell because of the way he skates.
"So efficient," said his defense partner Esa Lindell. "That's why he can play as much as he can play."
Duchene compared Heiskanen's skating to Hall of Fame defenseman Scott Niedermayer.
"It's just effortless and very rarely do you see him sprint," Duchene said. "He's always in that cruise but his cruise is really fast. I think he's a guy that can play through some stuff because of that. He's not a guy out there grinding to just move like a lot of guys are."
No, in fact, it doesn't look like he was recently dealing with an injury at all.
"We knew he was banged up," Oettinger said, "but we also knew, knowing him, he'll be back."
