Coach Michel Therrien said Pacioretty will sit out the opening game of their first round NHL playoff series against the Ottawa Senators on Wednesday night at the Bell Centre.
He said it is possible Pacioretty, who has an upper body injury, will be return for Game 2 on Friday night.
"As I said, we'll use him when he's 100 per cent," said Therrien. "It's not tonight obviously.
"It could be Friday, it could be Sunday. Once we get the OK from our medical team, we'll be very glad to get him back in the lineup."
Pacioretty, who had 37 goals and 67 points this season, stayed on the ice after an optional skate for some extra work along with the other players not likely to play, including defencemen Mike Weaver and Sergei Gonchar and centre Manny Malhotra.
Pacioretty was injured in Montreal's third-last regular-season game when he was checked into the boards by Florida's Dmitry Kulikov.