The Brazil international striker didn't start the first leg, which Milan lost 1-0, but his record of 11 goals in 17 League appearances this season mean he is a potent threat.
"Milan have every chance of going through," Zola told La Gazzetta dello Sport.
"Tottenham are a great team, but they are young and inexperienced."
Asked if he had any advice for Milan, Zola replied: "Play openly because they will not stand off so the defence should concede something.
"Milan should be clever at profiting from it. Paradoxically on a tactical level I would say that it will be simpler for Milan with respect to the first leg.
"They should focus on Pato. He could hurt the English with his speed."