The former Italy, Milan, Juventus and Inter coach has given the Spaniard his backing and feels the Naples-based club can pose a serious threat in the title race this term.
Napoli finished third in Serie A last season, a massive 24 points behind champions Juventus, and were dumped out of this year's edition of the Champions League by Athletic Bilbao in the play-off stage.
But Trapattoni was impressed with the way Benitez has handled that disappointment and, although he feels Juve and Roma both have better teams, the 75-year-old is sure Napoli have enough quality to produce an upset.
He told Il Mattino: "Balance in football is like a spider's web – one puff of wind and it can break. I am certain Benitez's Napoli can win this Scudetto.
"Perhaps he was wise to take some time off this week, as staying would've meant going back over the same errors and lighting that fire of controversy again.
"Being away is his way of saying he's got the situation in hand, everyone relax and we'll discuss it later.
"Juventus and Roma are superior on paper, but the reality is always more complex than that.
"Benitez has [Gonzalo] Higuain, [Jose] Callejon and all those quality internationals, but football is a moment, a lapse of concentration.
"My Republic of Ireland team went out of the Euros due to a mistaken throw-in at the 92nd minute."
Despite giving Benitez a vote of confidence, Trapattoni feels the Napoli job is one which engulfs the coach in too much pressure.
He added: "There is no patience in the south, even though it is the club with the best long-term plan that wins out.
"Every time Juventus were beaten in Europe, [former Juventus president Giampiero] Boniperti would arrive and reassure us it wasn’t a tragedy, so there was no need to cry and wail over it.
"We won at Juve because, unlike places such as Napoli and Roma, we did not experience those huge leaps from enthusiasm to despair.
"They continue to make the clubs in southern Italy unique in the world, but can also be frightening.
"You can’t win a game without being treated like a prophet or lose the next week and hear your job is hanging by a thread.
"I was often called to Napoli, first as a player and then a coach. I am enchanted by the city, but the pressure created around the team can really affect performances."
