Desharnais has an illness that prevented him from flying with the rest of the team Monday after missing Game 2 on Sunday. With an extra day off before the series resumes, there's time for Desharnais to make the trip himself.
"Before I make any decisions regarding the lineup, I need to find out if David is going to be available to play," Therrien said on a conference call Monday. "There's a possibility that he'll be there Wednesday night, but we're not quite sure yet."
Brian Flynn replaced Desharnais in the lineup for Game 2, a 6-2 loss at Bell Centre.
Desharnais has two assists in seven playoff games this spring.
Montreal trails the series two games to none.