Nilstorp was the backup to Richard Bachman before Tuesday's move. Bachman has made three straight starts since he had to replace starter Kari Lehtonen, who re-injured a groin early in a win over the Los Angeles Kings on April 9.
Bachman helped the Stars finish off a season-best five-game winning streak before Monday night's 5-2 loss to Chicago.
Nilstorp has bounced between Dallas and the Texas Stars most of the season. He's 1-3-1 with Dallas and 18-11-5 with Texas.
The Stars have two days off before playing Vancouver at home on Thursday night.
I remember the first time at Wrigley Field all of us had the long johns, the turtlenecks and the extra equipment because we were afraid of being cold. Halfway through the first period everybody's ripping everything off and we just ended up wearing what we would normally wear for a game at the United Center.
— Chicago Blackhawks forward Patrick Sharp on the 2009 Bridgestone NHL Winter Classic