Johnson, the team's sack leader with 8.5, has missed the past two games. Williams, the team's leading rusher with 610 yards, missed Sunday's 27-6 victory over Tampa Bay. Blackburn and Hartsock have missed the past three games.
Rookie A.J. Klein has played well in replacing Blackburn. Rivera said it hasn't been determined if Blackburn will retain his starting spot even though he was playing well before the injury.
"We'll see,'' he said. "We're going to play the guys that gives us the best chance to win the game.''
The Panthers have won a franchise record eight straight games to improve to 9-3. They trail the Saints (9-2), who are at Seattle on Monday night, by half a game.