Partenopei are still unbeaten this season and sit second in the league. They are on the same points as leaders Juventus.
Matthaus, who played for Inter Milan between 1988 and 1992, said that Walter Mazzarri's midfield is the best in the league.
He also believes that his former team will put last season's disappointing finish behind them to end in third.
"I see Napoli as favourites for the Scudetto," the 51-year-old told Calcio Napoli 24. "They are a very organised team and they have a very good midfield.
"I like their Swiss trio of Gokhan Inler, Valon Behrami and Blerim Dzemaili. They could come first, ahead of Juventus.
"I think Inter, Lazio and Fiorentina will finish behind Napoli and Juventus and in that order. Roma will be next."
Matthaus won 150 caps for Germany.