A Friday morning hearing in New York has been set for Rypien, commissioner Gary Bettman and NHL disciplinarian Colin Campbell, league sources told ESPN.com's Pierre LeBrun.
While headed to locker room after being assessed a double minor for roughing and 10-minute misconduct in the second period, Rypien reached up and shoved James Engquist, a 28-year-old fan applauding at the railing.
Rypien was pulled away by teammate Manny Malhotra, and Engquist and his brother, Peter, were removed from the area.
"This was totally unexpected," Vancouver general manager Mike Gillis said Wednesday night during the Canucks' game in Chicago. "In our experience with Rick, we never expected anything like this to occur. He's been a solid guy on our team. He's a good teammate, good in the community. It was something completely unexpected. Sometimes things happen, and you have to deal with them. You don't anticipate any event like that from a player of Rick's stature. There were events that led up to it, and we're going to support him."
Rypien and Minnesota's Brad Staubitz, who fought in the first period, were about to square off midway through the second before being separated by the linesmen in front of the Wild bench. Rypien punched Staubitz while he was being restrained.
Engquist told the Star Tribune of Minneapolis that he's "definitely seeking legal representation. ... I was assaulted, that's just the bottom line."
"I was just standing straight up applauding as he was getting kicked out," Engquist said. "He was out of control. And then I said, 'Way to be professional,' and he obviously didn't care for that comment and decided to grab me and almost dragged me over the rail. If my brother wasn't grabbing me and the other player wasn't grabbing him, he probably would have dragged me over the edge."
Rypien, the cousin of former NFL quarterback Mark Rypien, was in the penalty box to start the third but didn't play in the period.
After the hearing, the NHL will determine the length of the suspension. Players can be suspended for five games or more if they are summoned for a hearing, although that doesn't mean they will be banned for that long.
The league has handed out five suspensions and four fines in the past 10 days.
"We'll let things unfold from here," Canucks coach Alain Vigneault said Wednesday night before the game. "I'm going to save my comments until after the league does their investigation and comes up with a decision."
The NHL's rulebook provides for the commissioner's office to discipline players who physically interact with fans.
Rule 23.7 states that "Any player, goalkeeper or non-playing club personnel who physically interferes with the spectators, becomes involved in an altercation with a spectator, or throws any object at a spectator, shall automatically incur a game misconduct penalty and the Referee shall report all such infractions to the Commissioner who shall have full power to impose such further penalty as he shall deem appropriate."
"They always look at previous experience and whether there's a tendency or prior history in this type of event," Gillis said. "We're hopeful they'll consider every factor. We're going to work with the league, abide by their decision and get the best result we can for Rick and our team."
Rypien didn't travel with the team to Chicago.
ESPN.com hockey writer Pierre LeBrun and The Associated Press contributed to this report.