Juventus have returned to the top flight after their series of poor results. Slowly, their position in the Serie A standings is getting better. The match against Napoli in January is very important for the Old Lady to win to close the gap with them. But to target the Scudetto seems to be very difficult to realize. Napoli have put in some amazing performances, but we don't know how they will fare after the World Cup.
After the world cup, there may be differences in appearance for some of the top teams in Serie A, especially for teams whose players are used in world cup matches. Of course they will be very overwhelmed and tired, even potentially injured. But in general Napoli will still try to perform well after the world cup because not many of their players have been involved or called up by the national team in this world cup.