Callahan, who is considered day-to-day, suffered the injury Monday night against the New Jersey Devils, but was not forced to leave the game. Newly acquired John Scott will take his place in the lineup.
Callahan has 25 goals this season, second-most on the team.
This team has been a real treat to say you've been the head coach of them. I'm extremely proud of this group ... after the disappointment of (the Game 6 loss) is digested, it's always a lot easier as a coach when your team has emptied its tank, and that team emptied its tank for me for three months.
— Senators coach Dave Cameron after getting eliminated in the first round by the Canadiens