The former Chelsea forward made the comments despite Napoli having a poorer defensive record in their domestic league – conceding 16 goals in 13 matches compared to Liverpool’s 13 in 13.
But in Europe, Liverpool have conceded seven to Napoli’s three.
“Losing Lorenzo Insigne is a real blow [Napoli’s captain misses the game with an elbow injury], but the Azzurri already proved they know how to beat Liverpool,” Zola Italian newspaper Il Mattino.
Zola added: “It’s true that the Reds have a very strong attack, but their defence is hardly a blockade.
“With the creativity of their players, Napoli can cause real problems.”
Zola did, however, praise the atmosphere at Anfield and conceded it would have its usual part to play for a side badly in need of a turnaround.
He said: “Anfield is a unique stadium in the world, one that gives its team an extra boost.
“It’s difficult to explain the atmosphere, both inside and outside the arena. It’ll be important to face them with a calm mentality.”
Zola, who played more than 130 games for Napoli in the late 1980s and early 1990s before cementing his legacy at Chelsea, said: “It’s not a good moment for Napoli right now, but nights like this can spark a rebirth.”
The Italian’s comments came in the wake of a “mutiny,” as described in the local press, in the Napoli camp stemming from the squad’s reported refusal to attend a training retreat earlier this month.