The NHL fined McQuaid US$2,500 on Thursday for the incident that occurred late in the second period of Boston's 5-2 win.
McQuaid stuck his knee out to impede Foligno at the Ottawa blue-line as the Senators left-winger looked to exit the zone.
The Charlottetown native was handed a five-minute major and a game misconduct. Foligno, who played junior hockey with McQuaid, had to be helped to the bench and went to the locker-room, but returned to action a short time late.
Foligno said after the game that he didn't think his former teammate would intentionally try to injure him, or any other opponent. He added McQuaid's knee made the majority of its contact with Foligno's thigh.
The fine levied on McQuaid is the maximum allowed under the collective bargaining agreement. The money goes to the Players' Emergency Assistance Fund.