Allegri not taking risks on Vidal and Pogba
Vidal has been contending with groin and back issues, while the fitness of Pogba (thigh) is also a concern with both players set to be assessed on Sunday.
Allegri is hopeful both players can feature at Rome's Stadio Olimpico, but will not take a chance on their availability despite the importance of the game.
"They are doing fairly well and I'll evaluate them in today's training session," Allegri said.
"If they are in good shape, then they will play, otherwise we have those who can replace them. There is Claudio Marchisio, Stefano Sturaro, Simone Padoin and Roberto Pereyra.
"We could even decide to play with only two midfielders. This is only one game and I don't want to risk losing someone for a month. We've already lost [Andrea] Pirlo, it would be stupid to risk another.
"My tactical decisions will also be based on who is at my disposal. Until I know that, I can't pick an approach."
Juve take a nine-point lead to the capital and another victory would leave the Turin club well on the way to defending their Serie A crown.
But Allegri insists that the destination of the title will not be decided in Monday's game.
"We have a nine-point advantage, but there are many games to go," he added.