But all was made right on Thursday.
Chara said he was "OK" and X-rays on his ankle were negative, the Bruins reported on their Web site.
"Anybody in that position would go down and block the shot," Chara was quoted as saying on the Web site. "I know it is preseason, but, hey, why not start now ... I had an x-ray. It's negative. It's just a bone bruise."
Chara, who left Ottawa as a free agent to sign a five-year, $37.5 million deal with Boston, was hurt when he blocked Sheldon Souray's slap shot during Montreal's 5-on-3 power play early in the first period. Chara remained in the game through the first period and scored Boston's first goal in an eventual 3-1 win.
"We can sleep now," Bruins coach Dave Lewis was quoted as saying on the Web site. "It was a bit of restless evening, once I got home from [Montreal] and I think [GM Peter Chiarelli] had the same thought process ... if we had to play a regular-season game tomorrow, I'm certainly sure he could play."