Both clubs are mired in a crisis with Milan, already on to their second coach of the season, languishing in mid table and Napoli's title challenge having apparently run out of steam after barely one third of the season.
Runners-up in three of the last four seasons, Napoli have dropped to seventh, 13 points behind leaders Juventus, after a run of five matches without a win in all competitions.
Stefano Poli's Milan, meanwhile, are 14th place with 13 points, only four clear of the relegation zone. They have won only four league games out of 12 all season and scored a measly 11 goals.
Meanwhile, at the top, leaders Juventus (32 points) visit Atalanta and second-placed Inter Milan (31) travel to Torino, both on Saturday.
Milan spent heavily during the close season yet their form is so poor that the speculation has already started over who they might sign during the next January transfer window.
Several Italian newspapers have reported that the club has been in talks with 38-year-old Zlatan Ibrahimovic over a possible return. The Swede previously played for them between 2010 and 2012.
Napoli's season is threatening to come apart following a rift between coach Carlo Ancelotti and his squad on one side and the club on the other.
The club has threatened to take legal action after the players refused to be confined to a week-long training camp following a 2-1 defeat to AS Roma earlier this month.
Since then, the silence from Napoli has been deafening as the club has imposed a media blackout, refusing to let Ancelotti and his players take part even in post-match television interviews and media conferences which are compulsory under competition rules.
The club's website has posted only minimal details about training sessions and how players performed with their national teams during the last few days.
The silence was broken only between Elif Elmas who spoke to reporters while with the North Macedonia national side and by Ancelotti who spoke during a conference on the VAR system on Tuesday.
Elmas said he believed that the title race was not over yet, earning a quick rebuke from the club.
"Elmas spoke to the press without the club's authorisation during the current media blackout," said a Napoli statement. "Napoli therefore reserves the right to take action against the player."
(Writing by Brian Homewood, editing by Pritha Sarkar)