Chara, the 6-foot-9 defenseman, missed Game 2 on Saturday with what the team said was a case of dehydration. Chara did not speak to the media.
Kostitsyn missed Game 2 with a foot injury. He was skating on the right wing with center Tomas Plekanec and Michael Cammalleri.
Kostitsyn was injured while blocking Chara's shot in Game 1.
Montreal leads the series 2-0.