Matthews missed Friday's win over the Edmonton Oilers after getting banged up in Wednesday's loss to the Oilers. No specific diagnosis was given by the Maple Leafs, with head coach Sheldon Keefe only saying Matthews was out for precautionary reasons.
Matthews has two goals and five points in five games this season. Adam Brooks, who scored in Friday's win, was removed from the lineup to make room for Matthews.
In other lineup news, Jack Campbell will make his second start of the season for the Maple Leafs Sunday. And forward Dillon Dube is out of the lineup for the Flames with a lower-body injury.