Napoli goalkeeper Gennaro Iezzo admits they must adjust quickly to Serie A pace if they're to avoid being sucked into a relegation battle.

"We need to wake up right away or we will hit a vicious circle and be in trouble by October," the experienced custodian growled after their opening day defeat to Cagliari.

"Serie A is difficult and you don't just survive because of the club badge. We need to keep our feet on the ground and battle for safety.

"At this level one moment can undo you like Alessandro Matri's goal on Sunday. We lost to a Cagliari side who aren't exceptional, but they have players with more top-flight experience than us."