Volchenkov elbowed Marchand along the boards at 15:11 in the second period. The Bruins winger needed to be helped off the ice and through the tunnel.
Boston general manager announced Marchand sustained a 'mild' concussion on the play in a statement Thursday evening on NHL.com.
He added that the team will provide further updates 'when appropriate.'
In his player safety video, NHL disciplinarian said what could have been a clean hit instead turned into a "reckless" play that Volchenkov could have controlled, despite the fact Marchand stands five-foot-nine.
Boston raced to a four-goal lead before holding on for a 5-4 win over New Jersey, who have fallen out of the playoff picture in the last two weeks.
Volchenkov will miss the team's games against Ottawa, Toronto, Philadelphia and Florida.
The 31-year-old Russian blue-liner will be eligible to return on April 21 against the New York Rangers.
For the season, he has one goal, three assists and 37 penalty minutes in 33 games.
Volchenkov, who will also forfeit just under $92,000 US in salary, was previously suspended for an incident in 2011.