Boston Bruins forward Shawn Thornton has informed the National Hockey League (NHL) that he will appeal his 15-game suspension for punching Pittsburgh Penguins defenseman Brooks Orpik nine days ago.

Thornton, whose ban was announced by the NHL on Saturday, faced a 4 p.m. ET (2100 GMT) deadline on Monday to file his appeal.

"Shawn Thornton has decided to appeal the league's decision to suspend him for 15 games, and on his behalf the NHLPA has notified the NHL," the National Hockey League Players' Association tweeted.

Under the collective bargaining agreement, NHL Commissioner Gary Bettman will hear the appeal during an in-person meeting though Thornton, if he chooses, can appeal Bettman's ruling to a neutral arbitrator.

Thornton's actions, which resulted in Orpik sustaining a concussion, occurred during the first period of Boston's 3-2 home win against Pittsburgh on December 7 after the Bruins forward pulled the unsuspecting Orpik to the ice.

Thornton then punched Orpik several times in the head before he was assessed a match penalty, ejected and immediately suspended.

"This cannot be described as a hockey play that went bad, nor do we consider this a spontaneous reaction to an incident that just occurred," the NHL said in a video link posted on its website.

"Rather, 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."

Media reports after the game said Thornton was angry because Orpik's hit to Bruins forward Loui Eriksson during the first shift knocked the Boston forward out of the game.

Thornton, who had a hearing with the league's player safety department in New York last week, expressed remorse for his actions.

"I feel awful," the Bruins forward, who has three points in 27 games this season, told reporters after the December 7 game. "It wasn't my intention for that outcome. I know Brooksie. I've gotten to know him over the last seven years here.

"I skate with him in the summer and through the lockout. I've texted him a couple times. It's not what I wanted to see or what anybody wanted to see."