The Reds begin their defence of the title with a tricky game against the talented Italian outfit.
And Klopp knows that if his side are not at their best, Napoli will be happy to pounce on any weaknesses.
The last time these sides met in Naples, the home side won 1-0 through a Lorenzo Insigne goal.
"We talk a lot about intensity," Klopp said about the game to reporters.
"The Napoli game last season was not intensity. It was an organisation problem.
"We were just not… all the things we do, all the things we tell the boys, it is all about intensity and how much we have to invest, but before that it is all about information, what do you have to do in these moments?
"And Napoli plays a specific style. To make it very simple, we played against them in our defending like they had one No.6 but they had two sixes, the cheeky bastards!
"We knew before [the game]. We told them they had two sixes, but then everyone came too late and that was when it started. We tried to change it in the game and nobody listened and nobody could change. In the end they were lucky they scored [a late goal] but we were lucky it was only 1-0. It was really this kind of off day."