The incident took place Monday in a game Edmonton won 4-3. The NHL released a video of the incident and a statement from Brendan Shanahan, the league's director of player safety.
"This is a 50-50 puck that either player can win," Shanahan said. "In such cases, a reasonable amount of physical contact is permissible as the players jostle for position.
"On this play, Carcillo slows up and gets behind Gilbert. Just as Gilbert begins slowing down and bracing himself for some contact, Carcillo explodes into him, causing a violent crash into the boards.
"This is a clear violation. Not only does Carcillo not minimize contact, he hits Gilbert into the boards with tremendous force. At an extremely dangerous distance from the boards, Carcillo finishes high and hard with his hands, using the boards as a weapon."
Carcillo was suspended for two games this season for what the NHL said was an illegal hit to Carolina defenseman Joni Pitkanen.
He will forfeit $66,158.54 in salary, which goes to the Players' Emergency Assistance Fund. Carcillo will be eligible to return Jan. 18.
NBC reportedly holds celebs hostage to Jimmy Fallon's show
Ray Liotta sues skin care company over use of likeness