Dallas is the second seed from the Western Conference after finishing the regular season with 112 points. Minnesota is the third seed and had 104 points.
"Honestly, we'll know tomorrow night whether he's going to be a player on Saturday," Stars coach Glen Gulutzan told NHL.com on Thursday. "We have the 4:30 (CT) game, so we won't even have the morning skate that day, so we'll have to make a determination tomorrow night to see where he's at and then go from there. We're not 100 percent sure. We're hopeful. I'm hopeful. But we've got two plans for what we will be doing if he's in or if he's out."
Heiskanen has not practiced with the team since sustaining a lower-body injury in a 5-4 win against the Wild on April 9. He missed Dallas' final three regular-season games.
"He skated by himself, but we'll see where he's at in a team practice," Gulutzan said.
Heiskanen finished the regular season ninth among NHL defensemen with 63 points (nine goals, 54 assists) in 77 games. That included 28 points on the power play, which was tied for fourth at his position. The Stars were second in the NHL with the man-advantage at 28.6 percent.
Heiskanen also averaged the fourth-most ice time per game of any player in the regular season (25:28).
In his absence, the Stars have used Thomas Harley on their first power-play unit. They went 3-for-10 in that span and Harley had an assist on one of the goals.
"I think 'Harls' gives us a really good shot presence, he's prepared to shoot," Gulutzan said. "Miro is more of a distributor, but it doesn't change a whole lot. Each guy has his own little skill set, but it adds to the power play rather than take away. That's a good thing. It's a little dynamic when both guys bring their own flavor to the party."
Dallas will be without center Roope Hintz for at least Games 1 and 2 because of a lower-body injury. Hintz has not played since March 6.
