In overtime, Ference sent McDonagh crashing into the boards and was assessed a five-minute major for charging and a game misconduct on the play. The Rangers scored on the ensuing power play to win the game.
"It was one of the most dangerous hits I've seen in a while," Rangers head coach John Tortorella said. "Nothing needs to be said about what has to be done."
McDonagh, who suffered an upper-body injury on the play, remained on the ice for a few minutes before he skated off with a trainer.
Ference acknowledged the danger in the play he made.
"The five minutes, obviously, didn't help the team, but on top of that you just hope you didn't put a guy in a bad spot," said Ference, who scored for the second consecutive game. "It's a bad feeling both ways."
Bruins head coach Claude Julien defended Ference and his style of play.
"Andrew Ference is not a dirty player," Julien said. "He's a guy who is trying to support what the league is trying to do as far as preventing injuries."