The potent attacking lineup will face a struggling Chelsea in Italy on Tuesday evening but Blues boss Villas-Boas still believes his side has a good chance of progressing through to the next round.
"[Edinson Cavani] is an amazing player," Villas-Boas told reporters. "To be fair, [Napoli's] strength is in the collective spirit.
"They have an inner belief in each other. They have a strong front three with [Marek] Hamsik, Cavani and [Ezequiel] Lavezzi. They are a danger."
Chelsea have been in poor form recently, enduring a run of just one win in four games which includes a draw against Championship side Birmingham in the FA Cup on Saturday.
But Villas-Boas claims that the Champions League is a different type of football and his side have a good chance of progressing to the next round.
He added: "It's a different competition. Napoli come into the game after a good result - not after a good run because they've been inconsistent recently - but won well at Fiorentina.
"It's a different type of preparation, different type of football, European football, played in a different way. We will have to be much more competent, play well and try to take the game to Stamford Bridge.
"If you go past Napoli then you can have a really good chance, depending on who you get in the draw. If you get a good draw. First Napoli, then we will see who we draw out and then we will see.
"But I think we are in with a really good chance. It will be a massive challenge. Everyone saw what Napoli did in a group which put [Manchester City] out. We just have to be extremely strong to go through.
"Regarding the Champions League, the players will have a differenet outlook. It's a European game, all of the players will want to play. The Champions League is a competition that everyone wants to win.
"There are two weeks between the games and it's important for us to be competent and to bring the game to Stamford Bridge with a win or a draw, ideally a scoring draw. Then we can finish the business here."
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