Chabot suffered the injury while blocking a shot on Monday night in Philadelphia.
Senators head coach Marc Crawford said Chabot hopes to return before the end of the season.
Head coach Marc Crawford announced the injury Wednesday.
Chabot is the leading scorer for the NHL’s worst team, registering 49 points (13 goals and 36 assists) in 62 games.
Meanwhile, college free agent signing Max Veronneau practised with the Senators for the first time on Wednesday.
The Ottawa-born Princeton product is expected to make his NHL debut on Thursday against the visiting St. Louis Blues.