Brendan Shanahan, the NHL's senior vice president of player safety, announced the suspension Monday afternoon.
At 11:06 of the first period, Marchand lay on the ice in front of the Bruins' bench when Neal skated by and his knee made contact with Marchand's head. Marchand was shaken up on the play and tended to by a team trainer before going to the locker room.
Neal was given a two-minute minor for kneeing. Marchand returned to the bench a few minutes later and remained in the game.
"With a clear view of Marchand, and plenty of time to avoid him, Neal skated directly through Marchand's head with his left knee," Shanahan said in his video discussing the suspension.
"While looking down directly at Marchand, Neal turns his skates and extends his left leg, ensuring contact is made with Marchand's head," Shanahan said. "While Neal does not kick or violently thrust his leg toward Marchand, it's our belief after reviewing this incident that this is more serious than simply not avoiding contact with the fallen player."
Boston coach Claude Julien said the Bruins, who play the Flames in Calgary on Tuesday, are moving ahead.
"No comments, really," Julien told reporters in Calgary. "The league took care of it and that's where it ends. We've got to move on here. I know [Shawn] Thornton will be next on the list for our team for what happened on Saturday night, so we'll wait and see what happens there.
"You've got to move on from those things. Move on doesn't mean you forget what happened. We all have to get better about it and try to minimize those situations." Thornton will have an in-person disciplinary hearing with the NHL for punching Brooks Orpik, who was put on injured reserve Monday with a concussion.
Shanahan also said the league could not ignore the fact Neal has been fined once and suspended twice in the past, even though he's not considered a repeat offender under the CBA. Neal will forfeit $128,205.15 in salary. The money goes to the Players' Emergency Assistance Fund.