Boston Bruins forward Shawn Thornton was given a 15-game suspension by the NHL for attacking Pittsburgh Penguins defenseman Brooks Orpik during a Dec. 7 game at TD Garden, the league announced Saturday.

Because Thornton was assessed a match penalty for the incident, he by rule has missed the Bruins' past three games while he awaited Friday's in-person disciplinary hearing with the NHL in New York.

"This cannot be described as a hockey play that went bad, or do we consider this a spontaneous reaction to an incident that just occurred," NHL vice president of player safety Brendan Shanahan said in the video announcing the suspension. "It is our view that this was an act of retribution for an incident that occurred earlier in the game, the result of this action by Thornton was a serious injury to Orpik."

The suspension is the first of Thornton's career. He will forfeit $84,615.45 in salary.

"I am aware of today's ruling by the NHL Department of Player Safety. I will be consulting with the Bruins, my representation and the NHLPA about next steps, and will be in a position to address the matter publicly after speaking with those parties," Thornton said in a release. "Until then I will have no further comment."

Thornton's agent, Anton Thun, said they would take a few days to figure out whether or not they'll appeal, according to ESPN.com's Pierre LeBrun.

Thornton had originally attempted to get Orpik to drop the gloves after his hit on Loui Eriksson resulted in a concussion, but Orpik would not oblige. During a stoppage in play at 11:06 of the first period, Thornton grabbed Orpik from behind, slew-footing him to the ice and punching him twice in the head. Orpik suffered a concussion and was taken off the ice on a stretcher and transported to the hospital. Orpik was released shortly after and cleared to return with the team to Pittsburgh, but he says he does not remember anything from the game.