Napoli have made a flying start to the campaign and lead Serie A with 38 points from a possible 42, suggesting that they can finally end Juve's run of six successive titles.
Juve have looked vulnerable by their own standards but even so are still only four points behind Napoli in third place, waiting to pounce at the first sign of weakness by their rivals.
Inter Milan, who host Chievo on Sunday and like Napoli are still unbeaten, are sandwiched in between on 36 points.
Napoli, alongside AS Roma, have been the only real threat to Juve's dominance in the last few years but the Turin side have made a habit of winning the key duals between the pair.
Last season, Juventus won 2-1 at home, drew 1-1 in Naples and also beat Napoli over two legs in the Coppa Italia semi-final.
With only seven points separating the top four teams, there has been an unusually friendly build-up with both coaches agreeing that, whoever wins on Friday, there will be time for their rivals to recover.
“If we win we’d have an important advantage over Juventus in the standings, but it won’t be a decisive game because there are a lot of games to go," said Napoli coach Maurizio Sarri.
“Juve won’t be out of it, they’ll play right to the end of the season because they’re a great team.”
He added: “I don’t think the table means too much at the moment. I view this as a prestigious match which has a special meaning for our fans but I don't see it as that important for the table." Sarri's opposite number Massimiliano Allegri echoed his sentiments after his side beat Crotone 3-0 on Sunday.
"The target is to get to March, still be in touch with the leading group and be ready for the final sprint," he said.
"We have played some excellent football, and Napoli have been extraordinary, but it’s a long season and it doesn’t really matter at this point whether you are a couple of points ahead or behind." Juventus forward Gonzalo Higuain underwent surgery on his left hand on Monday and it is not clear whether he will be fit to face the club he left in acrimonious circumstances last year.
It will also be an intriguing weekend for AC Milan where their former midfielder Gennaro Gattuso makes his debut as their new coach after replacing Vincenzo Montella.
Milan are away on Sunday to promoted Benevento who have lost all 14 games so far.
(Reporting by Brian Homewood; Editing by Toby Davis)
