The Partenopei boss wants his side to be more ruthless and prevent teams from getting back into the match after a 2-0 win against Sampdoria
A second-half double from Dries Mertens secured the three points for Benitez's team, but the coach expressed his concerns after an open game that saw the Blucerchiati hit the woodwork twice.
“The team had many scoring opportunities and could’ve made the difference in the first half. The game was more open in the second and they caused us problems, but we got the goals,” said Benitez, speaking to Sky Sport Italia.
“I would like to see us stronger in defence and quicker at finishing games off, but it’s reassuring to see such attacking football. This is an attack-minded team and it’s something we have to take into account when looking at how we defend."
Mertens put Napoli in the lead thanks to a Gonzalo Higuain assist, before getting his second goal with a deflected free kick, and Benitez was pleased with the pair's efforts.
He added: “Yesterday Mertens practiced free kicks and we know Gonzalo Higuain is very good at finding his teammates."
Napoli face Verona in the league on Sunday, but Benitez isn't worried about the absence of Marek Hamsik, who is still on the sidelines with a foot injury.
“Marek did very well at the start of the season playing behind the striker," he said.
"He needs to get back to 100 per cent fitness, but Goran Pandev, Jose Callejon or Hamsik can all play there. It’s just a matter of finding the right balance.”