The Partenopei finished second behind Juventus last term under former coach Walter Mazzarri, who left in May to take up a post with Inter.
And, as he looks to leave his own stamp on the Naples club, Benitez is pleased with what he has seen so far in the pre-season.
"The evolution of the team is continuing," Benitez told the Napoli website. "Every week and with every game you can see that they are improving.
"In my opinion it has been really good. The players' commitment is there, everyone is working very hard, and everything around the Dimaro training camp is fine. I was really pleased.
"The team has been adapting to a new manager, new ideas and we changed the system, the way that we train. You can see during the games we've already played that they are enjoying time with the ball, working hard in defence.
"Tactically the team is different, but they are trying to do their best."
Napoli begin the Serie A season with a home clash against Bologna on August 25, and Benitez has predicted exciting times ahead for supporters.
"The club is making a step forward. I have 16 players away on international duty, which is a record for the club and shows the international nature of the team," he said.
"The side is growing, the city is enjoying it and the fans are behind the team, so that is a key factor for us.
"When you see the fans behind the team with the level of play that we have at the moment ... I don't know what can happen, but I'm sure we will be very, very competitive."