Chara was apparently hurt on an innocuous-looking collision with Islanders forward John Tavares in the first period of the game in Boston. Chara didn't seem to be injured after the hit and continued to play for a time before leaving the game.
Bruins coach Claude Julien offered no information on Chara's status following Boston's 3-2 defeat, but multiple reports said the 37-year-old defenceman suffered ligament damage in his left knee, will be out of the lineup for four to six weeks and could be facing surgery.
A regular Norris Trophy candidate — he won the award as the NHL's top defenceman in 2009 — Chara helped the Bruins win the Stanley Cup in 2009. He has missed no more than five games in any of the last eight seasons.
The 6-foot-9 Slovakian is in the fourth year of a seven-year, $45.5-million US contract.