"I hope not," he said of Smith, tied for the team lead in receptions with 63. "I don't think it is."
But Rivera was pretty certain that running back Jonathan Stewart, who suffered a slight MCL tear in his right knee against New Orleans two weeks ago, won't return for Sunday's rematch against the Saints.
Rivera said Stewart, who was re-evaluated on Wednesday, remained on target for a possible return in the regular-season finale at the Atlanta Falcons.
Carolina (10-4) will again feature running back DeAngelo Williams in a game that could decide the NFC South champion and a first-round bye in the playoffs.