Wisniewski and Avery jostled in front of the Islanders' net after the play was stopped in the first period. Wisniewski made the gesture with his hand and mouth at Avery as the two were separated by officials.
While the crowd was small -- announced attendance was 11,748 -- commissioner Gary Bettman was in attendance to see the Islanders' 6-4 victory.
He said he heard about what happened but hadn't seen it. Bettman declined to comment and said any potential disciplinary action would be handled by the league's hockey operations department.
"My guess is hockey operations will do what needs to be done," Bettman said. "I don't react to things that are described to me."
Wisniewski said he didn't remember making a gesture, but video of the incident was on the YouTube website before the game was over.
"When are these players going to figure it out? We do have cameras at games," a league source told ESPN.com.
Avery was only 23 games into a four-year, $15.5 million deal with the Dallas Stars in December 2008 when Bettman suspended him for six games for a crude remark Avery made about ex-girlfriends dating other hockey players. The suspension was actually the culmination of a series of transgressions that included a vile diatribe against a fan in Boston a month earlier.
Avery also underwent counseling for anger management. That incident ended Avery's time with the Stars and led to his return to the Rangers that season after a stint in the minor leagues.
"It's pretty obvious what the guy was doing," Avery said of Wisniewski, "but I'm sure nothing will happen to him because nothing ever happens. It's interesting, he'd get a warning for something like that.
"Can you imagine if I did that? They sent me to rehab the last time I did something. It's crazy."
Before the season started Chicago defenseman Nick Boynton was suspended for a regular-season game for making a throat-slashing gesture during a preseason game against Tampa.
Scott Burnside covers the NHL for ESPN.com. Information from The Associated Press contributed to this story.