Despite winning only four out of eight games this year, leaders Juventus have opened a six-point gap over second-placed Napoli who have scored only one goal while drawing their last three league games.
It is no coincidence Napoli's loss of form has come at the same time as a six-match sequence without a goal for Uruguay forward Cavani, their talismanic striker who is on the radar of Europe's richest clubs.
Cavani has failed to hit the target at all in February, including two Europa League ties against Viktoria Plzen, but remains Serie A's top scorer with 18 goals.
A Napoli victory would throw open the championship race while a win for Juventus which give them an almost unassailable lead as they chase their second successive title.
"Psychologically it could be decisive," midfielder Valon Behrami told Napoli's website.
"It will give us an idea of who we are and what we can do this season. They have six points more than us and are experienced and confident."
Juventus, however, played down the importance of the game.
"It won't be decisive as far as the destiny of the title is concerned," said midfielder Stephan Lichtsteiner. "There will still be 11 games remaining after it.
"I know what the atmosphere will be like at the San Paolo but I'm not worried by it. We'll just have to react to it like we did in Glasgow against Celtic," he said referring to their 3-0 win in the Champions League earlier this month.
"They are an excellent side and it's difficult for anyone to play at the Stadio San Paolo. It won't be easy," added Lichtsteiner.
Juventus have 58 points from 26 games, with Napoli on 52.
NEW LEASE OF LIFE
There is another important clash on Saturday when Lazio, third on 47 points, visit fourth-placed AC Milan who are two points behind them.
Milan, undefeated this year in Serie A, have overcome a woeful start to the season and the arrival of striker Mario Balotelli from Manchester City has given the club a new lease of life.
Only the top two teams qualify directly for next season's Champions League group stage while third place earns a berth in the final qualifying round.
For the second time this season Gian Piero Gasperini will make his debut as Palermo coach when they visit Torino on Sunday.
Gasperini, fired one month ago by the Sicilian club, has bizarrely been handed back the reins after his replacement Alberto Toresani was dismissed after three games.
Bottom-of-the-table Palermo are without a win in 12 league games.
