Parros was stunned by a pair of late punches in a fight with Eric Boulton in Montreal's 1-0 overtime road win over the New York Islanders on Saturday. Parros was wobbly getting to his feet, but skated off the ice.
He didn't return to Saturday's game and was a scratch for Montreal's 2-1 home loss to Florida on Sunday. Canadiens coach Michel Therrien confirmed after the game that Parros suffered a concussion and will be evaluated this week.
Parros missed the first month of the season after being injured in a fight with Toronto's Colton Orr in the opener.
Parros was knocked unconscious after a tussle with Orr brought him tumbling to the ice.