The Avalanche forward waited until Roussel had removed his helmet and was engaged with the linesman before jabbing him in the temple.
In the dying minutes of Satuday's Colorado Avalanche win over the Dallas Stars, Avs forward Blake Comeau delivered a sucker punch to the head of Stars winger Antoine Roussel after a scrum had been broken up by the linesmen.
Rouseel, whose arms were being held by the linesmen when the punch was thrown and who had used his far hand to remove his helmet immediately prior, was knocked to the ice by the gloved punch.