The NHL team said Tuesday that Berard suffered the injury in a 4-3 overtime victory over the visiting New Jersey Devils last Saturday. Berard, 30, was signed to a one-year contract this month after attending training camp as an invitee. He has two goals and two assists in five games this season. Both of his goals were game-winners scored on the power play.
Islanders head coach Ted Nolan said Berard's play is a big reason why the team has the top-ranked power play in the NHL, entering Tuesday's games.
"I'm confident Bryan will do everything in his power to get healthy and back in the lineup soon," Nolan said in a statement. "The good news is our blue-line has a lot of depth, so this is an opportunity for other players to step up."
The Islanders' next game is Saturday night against the Carolina Hurricanes. The Islanders play just five games, all at home, in the next three weeks.
In 570 career games with the Islanders, Toronto, New York Rangers, Boston, Chicago and Columbus, Berard has 73 goals and 232 assists for 305 points.
Berard, a native of Woonsocket, R.I., has had an eventful NHL career. In 2000, he suffered a severe eye injury while playing for the Maple Leafs.
He also tested positive for steroids in early 2006 but wasn't disciplined by the NHL because the test was not part of the league's program.