“I have told them to sort it out between themselves,” said Emery.
“I think that they are capable of doing that and that they will both be our kickers. If they cannot reach an agreement, I will decide for them.”
He added: “I do not want this to become a problem for us.”
The home side struggled to make chances until Marcelo turned Cavani’s flick into his own net, with the second coming from a rebound off Jeremy Morel after Kylian Mbappe’s shot was pushed onto his knee by onrushing keeper Anthony Lopes.
In between the own goals, Cavani’s spot-kick, awarded when Ferland Mendy bundled Mbappe to the ground, had been well saved by Lopes.