Boychuk hit Toews in front of the Boston net in the second period, causing the Blackhawks captain to hit the ice hard. Toews left the game with an undisclosed injury.
Boychuk was not penalized on the play.
Toews, who is likely to play in Game 6 on Monday, did not speak to the media after the game but was seen signing autographs for fans on his way out of the United Center.
Blackhawks head coach Joel Quenneville called Toews day-to-day with an upper-body injury.