Not since the days of Diego Maradona in 1990 have Napoli won the Serie A title.
But halfway through the 2022/2023 season, Luciano Spalletti's side find themselves 12 points clear of second placed AC Milan ahead of this weekend's fixtures.
AS Roma are 13 points behind Napoli in fifth place.
Mourinho's men will have to be at their very best if they are to take anything away from the Stadio Diego Maradona against a side who have only lost once all season.
Mourinho, who celebrated his 60th birthday in the course of the week, believes Napoli have already wrapped up the title despite 19 round of matches still left to play.
"I'll say what I always say: they have already won the Scudetto, and deservedly so," Mourinho said at Saturday's pre-match press conference.
"They are an excellent team, with an excellent coach in Luciano Spalletti. They are now 12 points ahead and there are no teams that scare them. The Scudetto is theirs.
"We won't just step out of the way for them, but they have already won the championship. Congratulations to them."
