Coach Jacques Martin said on Saturday that Mara would be examined by team doctors to determine how long he will be out of action. Ryan O'Byrne took Mara's spot in the lineup at home Saturday night.
The veteran was injured in Montreal's 3-1 win at New Jersey on Friday night.
Forward Sergei Kostitsyn returned against New York after missing 10 games with an ankle injury.
The Associated Press contributed to this report.