Hejduk is out with an upper-body injury, while Mueller has been sidelined the entire series with a head injury.
The series is tied at two games apiece.
Hejduk left Sunday's 1-0 overtime win early in the first period after a collision with teammate Paul Stastny as they drifted into the Sharks' zone. He was held out of a 2-1 overtime loss on Tuesday.
Mueller hasn't played since taking a hit along the boards against the Sharks on April 4.
Forward Kevin Porter will available for Thursday. He's been out since leaving Game 2 with an upper-body injury.