Rafael Benitez's Napoli are well off the title pace in Serie A this season - currently lying 20 points behind runaway leaders Juventus - but Juve and Italy legend Del Piero, who now plays for Sydney FC, believes they will pose a stern threat in years to come.
"I think in future Napoli can fight for the Scudetto with Juventus," he told Il Mattino.
"(President) Aurelio De Laurentiis has planned very well and it still needs a little time to build a great squad.
"As for Juventus, their strength is that winning mentality.
"This team wins because it learned how to suffer when the results did not come. My (former) team-mates are doing extraordinary things."
Del Piero went on to laud Napoli's 22-year-old forward Insigne, who he feels has a bright future in the game.
"I really like Insigne, as I think he can go far," the FIFA World Cup winner added.
"I don’t think it’s wise to give advice, as he knows what he has to do, first of all to never stop cultivating and working on that talent. I wish him all the best."
Juve can take another step towards a third straight Italian title when they travel to Napoli on Sunday.
‘Scoring in a World Cup is like winning the title – can you imagine millions of people celebrating something you did? It’s insane and made me very proud’: Brazil legend explains how much 2002 goal meant to him
'He already had the ability but didn’t use it because he was afraid to shoot – I said, "You’re a player who has to decide games – you have to take risks, mate"': Liverpool star was forced to become confident by team-mates
