Dallas Stars goaltender Anton Khudobin got the start in Sunday's critical Game 4 versus the Calgary Flames.
The Stars have deemed Ben Bishop unfit to play, according to Sean Shapiro of The Athletic.
Bishop was also unavailable for Game 1. He started Game 2, then backed up Khudobin in Game 3.
The nature of Bishop's issue is unclear due to the NHL's policy prohibiting the publication of injury details during the postseason.
Jake Oettinger served as Khudobin's backup in Sunday's contest.
Calgary entered the game leading the series 2-1.
