"In Udine we must have character and confidence," he told Napoli's official website. "After Thursday's victory over Sparta Prague, we want to continue along this path by showing the same character and quality.
"Serie A is different to the Europa League. We are ready for this game against Udinese, who are a tough side. We'll face them with trust in our potential.
"I very much liked the reaction of the team against Sparta Prague and I'm convinced whoever plays tomorrow will show the same attitude to prove we are a strong squad."
Napoli finished third in Serie A last season and lifted the Coppa Italia.