Napoli performance can not be judged based on their preseason performance, I'm much confident that they are reserving themselves for the main competitions because they have a lot to battle with. They could have performed very well but there are many factors that was considered which I respect that. They are champions and they will like to continue in the path even though they aware that it going to be difficult.
I do not know why people still try to judge teams based on their preseason performance, a team like Napoli that is going through some sort of turbulent times that has brought in some strong uncertainties for their performance in the new season is not now you should judge based on the performance we see in the preseason. Napoli are indeed the champions and will want to continue that way maybe they could build the form for champions league but they still have instabilities now that they are yet to settle and I hope before the season starts they are in their best shape.