Hebert was mum about his condition, and coach Marc Trestman was cautiously optimistic the veteran will be ready to play when the Alouettes play host to the Toronto Argonauts in the CFL East Division final on Sunday.
''He's better today, the swelling's down,'' said Trestman. ''We did our best to keep him off his feet.
''We'll keep our fingers crossed but I'm sure (the decision) is going to go right to game time.''
Canadians Daryl Townsend and Marc-Olivier Brouillette, who is normally a linebacker but who has played safety before, have been working out at safety in Hebert's absence.
But if Hebert cannot play, it would be a blow to the Alouettes' defence and to its kicking game, where he led the league in special teams tackles with 28 this season.
''He makes a lot of calls and he's a physical presence on the perimeter and near the line of scrimmage,'' said Trestman. ''Plus he's a big factor on our special teams, so we've got our fingers crossed that he'll be ready to go.''