AC Milan's crisis threatens to deepen as the champions head into Sunday's derby with Inter, miles off the Serie A title pace and in a battle to reach next year's Champions League.

A full 15 points behind runaway league leaders Napoli and outside Italy's top four, Milan are possibly at the lowest point in Stefano Pioli's reign since a 5-0 hammering at Atalanta in 2019 almost led to his replacement as coach by Ralf Rangnick.

Pioli's team won just one of their seven matches in January in all competitions, extending what was a five-point gap between them and Napoli to the current chasm. They were also knocked out of the Italian Cup by Torino and were thumped by Inter in the Super Cup.

That loss to Inter in Saudi Arabia was the first of three humiliating defeats in as many matches, followed up by a 4-0 spanking at Lazio and last weekend's stunning 5-2 home defeat at the hands of lowly Sassuolo.

A sold out San Siro awaits both teams as Inter host the third and probably final derby of the season having supplanted Milan as Napoli's closest rivals for the Scudetto.

Despite Milan's collapse, Inter are only two points ahead of their local rivals and at the head of a pack of five teams separated by three in what looks to be an exciting race -- barring an epic Napoli collapse -- for the three remaining Champions League slots.

Roma, Lazio and above all in-form Atalanta, who are at Sassuolo on Saturday night, will want to take advantage of the two Milanese giants playing each other.

Napoli travel to struggling Spezia for Sunday's early match with a gale-force wind in their sails and the feeling that nothing can stop them claiming a first league crown since 1990.

In the aftermath of last week's dramatic win over Roma, owner Aurelio De Laurentiis was blocked at the exit of the Stadio Maradona by hundreds of delirious fans who danced around his car while roaring along to a trashy dance version of the chant 'il capolista se ne va', which can be roughly translated as 'we're running away with it'.

Spirits are so high down south, that De Laurentiis happily messed around with a fan in a phone call which quickly went viral on social media, during which he joked that pizza in Naples "was disgusting" and made an obscene suggestion on what the club's fans could do if Napoli do not win the Champions League.

His insult to the symbol of Neapolitan cuisine was so great that De Laurentiis then had to clarify in a statement that he was joking "apart from one thing: what I said about the Champions League".

It's a scarcely believable turnaround in relations between owner and supporters since pre-season, when enraged fans were demanding he sell, following the departure of beloved stars Lorenzo Insigne, Kalidou Koulibaly and Napoli's all-time top scorer Dries Mertens.

Player to watch: Rafael Leao

Dropped for last weekend's humbling by Sassuolo, Portugal winger Leao will be key to Milan's chances against Inter as they struggle with form and injuries, the latest a thigh problem for Algeria midfielder Ismael Bennacer.

In recent weeks, Leao has been a shadow of the player who lit up Serie A before the World Cup, but another display like the one which won this season's first derby, back in September, would go a long way to stopping the Rossoneri rot.

Key stats

13 - The points gap separating Napoli from the rest is the largest after 20 games since Serie A switched to three points for a win in 1994.

10 - The number of points Milan dropped in January.