A typically white-hot atmosphere is likely to await them at the Stadio San Paolo and, in a video posted on his YouTube channel, Brazil star Neymar issued a rallying call.
"It's a very difficult match, it will be a final for us," he said.
"We know we have to win this game and we hope to have a good match to get a great result.
"Again, we must approach it as if it were the last game of our lives."
Neymar has scored nine goals over the course of 10 Ligue 1 appearances this term and has three in three in the Champions League, although a hat-trick in the 6-1 demolition of Red Star Belgrade accounts for the latter tally.
A win for the Parisians in Naples would put them in a great position to qualify for the last 16 of this year's competition, with group leaders Liverpool facing a tricky away trip to Serbia to play against Red Star.