Japan boss Alberto Zaccheroni has warned Milan and Inter to not underestimate Napoli in the title race.
The Azzurri are currently second in the table, three points behind Milan and five points clear of fourth-placed Inter.
"A lot of people are underestimating this Napoli, but I wouldn't make that mistake," said the former Milan, Inter and Juve Coach.
"Napoli don't have the same squad strength as others, but if Inter and Milan don't take advantage of theirs then Napoli could profit."
Napoli's Scudetto hopes were boosted by Juventus' 1-0 defeat of rivals Inter in the Derby d'Italia on Sunday evening.
"Although Milan and Napoli are doing well, the championship is still open to Inter," Zaccheroni continued.
"Juventus? Last night's side were a much more compact one than they have been, but the difficulty is keeping this compactness against smaller and weaker clubs."
Juve have won their last two games in Serie A, but they haven't won three on the trot in the League so far this term. That could change at Lecce next week.