The team confirmed that Chara was hospitalized and received treatment for dehydration on Friday night.
"He got treated for a little bit of dehydration and that's basically all there is to that. Until our medical staff tells me he can't go, he's in tonight," said Bruins coach Claude Julien after his team's optional morning skate on Saturday.
Chara logged 25 minutes of ice time in the 2-0 loss to the Canadiens in Game 1 on Thursday night. He practiced and felt ill Friday afternoon, according to the Boston Herald, which first reported the hospitalization.
Chara played in 81 regular-season games before resting in Boston's final game of the season. He has missed just a total of 10 regular-season games, eight because of injury, in his five seasons with the Bruins.
"I think if it's up to him, he'll definitely play," Julien said. "The only people that'll hold him back are our doctors. That's the type of players you want on your team and he's got that attitude."
Some of Chara's teammates were not aware that the defenseman was hospitalized.
"I didn't know until last night," said forward Milan Lucic. "He's a battler. And I'm sure he'll do whatever he can to be able to get himself ready to play tonight."
The series shifts to Montreal next week for Game 3 and 4.