Matheson is dealing with a lower-body injury that will sideline him versus Buffalo on Tuesday, Eric Engels of Sportsnet reports.
Matheson has yet to find the back of the net through five games this season while registering just one helper despite averaging 24:09 of ice time. With the 32-year-old blueliner on the shelf, the Habs will get back to utilizing just six defensemen, which means Owen Beck will get into the lineup Tuesday. With the team heading into a back-to-back, Matheson may be hard-pressed to get into the lineup against the Caps on Wednesday.