Milroy, 24, has 52 points (23-29) in 52 games this season, his fourth in the AHL. The Edmonton native will make his NHL debut.
"He's having a good season," said Habs coach Guy Carbonneau. "He's leading the team in scoring. We need new blood and some offence."
He said the club considered recalling Andrei Kostitsyn, but he is unavailable because his girlfriend just gave birth.
Carbonneau also confirmed that David Aebischer will start in goal against Carolina. Jaroslav Halak, called up Friday from Hamilton, may get his first NHL start Sunday in Columbus.
Goaltender Cristobal Huet is sidelined with a hamstring injury.
Forwards Garth Murray and Aaron Downey were both scratched.