Italian legend Gianfranco Zola says Serie A needs AC Milan and Inter to be at their best.
Juventus have won the past five titles.
“Juventus are still the favourite for the final victory this season," Zola said on TeleRadioStereo.
“It's not a given that they'll win a sixth-consecutive Scudetto though. Juventus haven't yet been at their best, because they've changed a lot in the summer and they need to gel.
“That could be an advantage though, because it means they could do even more once they do reach their best.
“Other teams have to raise their level, and I'm not just talking about on the pitch, there's organisation too.
“There are clubs which are doing well, like Roma this year and Napoli last season.
“The Milanese clubs need to raise their level, and they're gearing up for that. That's what it'll take for the Italian League to return to being highly competitive."