Ahead of their return to Serie A action against Sampdoria on Monday, Napoli sit third in the table, having lost three league games in the season.
However, coach Benitez is keen to add players to his squad in an attempt to challenge Roma and Juventus for the title.
"The first thing I have to say is that I am very satisfied with the team we have available. Another thing is that we can improve, something that we always have to evaluate," the Spaniard said.
"We have to analyse the market, because we have economic capacity and the added advantage for any signing.
"But the signing has to be something better than what we already have in our side."
Benitez, who dismissed speculation that striker Duvan Zapata could leave Napoli this month, added that he had kept an eye on the Premier League, where he managed both Liverpool and Chelsea.
However, when talking about defensive additions, he did not feel there were players in the English top flight who could sufficiently boost his squad.
"I've been following the Premier League and have been watching many games in that competition. I have to say that I have not seen, for example, players of the level of Raul Albiol," he added.
"In the same way, it is difficult to find players such as Miguel Angel Britos and Fede Fernandez in the market.
"In any case, we work closely with (sporting director) Riccardo Bigon and all the estimations of the club is to look for a player that could be suitable for us. We are on it."
