The suspension means Volchenkov will half of the Devils' remaining eight regular-season games.
It's one game more than I thought he could get, but I'm not surprised the NHL went up to four after watching the video. Shanhan harped on a few things. One, Volchenkov extended his elbow to the point where it became "reckless elbow contact to the head" of Marchand. Two, Marchand tried to avoid the hit and turned his head, but it doesn't change the fact that Volchenkov didn't pursue the puck and turned what could've been a legal body check into an illegal elbow. Three, Volchenkov was in control of the play and in control of his body and clearly pursued the elbow to the head instead of playing the body. Shanahan also referenced Volchenkov's prior suspension and Marchand's injury (likely concussion) as factors, so at least the NHL admits a player's injury status affects how they rule. When you watch the video, it's hard to disagree with the four-game ban, which is often the case with Shanny's home movies.
The key here for the Devils is being able to field six legit NHL-caliber defensemen over a CRUCIAL four-game stretch. The Devils will face two non-playoff teams (Flyers and Panthers) but that's after playing the Senators on Friday and Maple Leafs on Monday. With Bryce Salvador banged up and currently owning a very bruised wrist, the Devils might be forced to go with Adam Larsson (which is fine) and Peter Harrold (which is probably not fine) against two good teams. It's just another hurdle this team has to overcome when they're already four points out of a playoff spot with two teams to jump to get to eighth place.