Juve have dominated domestically in Italy in recent years, winning three straight top-flight titles under the stewardship of former coach Antonio Conte.
This season's fight for the Scudetto has been largely considered a straight fight between Allegri's side and 2013-14 runners-up Roma, who are just three points adrift of Juve in second after 11 matches.
Napoli, who finished third last term, are starting to find form after a sluggish start and a 1-0 win at Fiorentina last Sunday followed the superb 2-0 victory over Roma.
And Allegri, who replaced now Italy coach Conte in the close-season, is keen to ensure Juve realise the threat posed by Rafael Benitez's side.
"Quite rightly, [Roma coach Rudi] Garcia is keeping Roma's confidence up. After all, it will be a fight to the very end," he told TG1.
"But Napoli are getting back into the running too."
Juve face Napoli for the Supercoppa Italiana in Qatar on December 22 and Allegri is hoping a win can be the catalyst for further silverware this season.
"Our first objective in terms of time is the Super Cup against Napoli, but we are also in the running for the Coppa Italia and the Scudetto," he added.
"Then there's the Champions League, which is a fantastic, intriguing and also difficult target. Our intention is to go as far as possible."
