Napoli don't have to worry much about the world cup and their players because they don't bring many of them compared to other teams and above all they are not players who can influence the championship so Napoli can rest assured
Break the transfer window and also the world cup will still have an effect on the team. Even though they are not part of the national team squad that represents their country for world cup. Example the physical and mental health of the players that will change when the league returns. This is something that the teams who are fighting for the championship need to be wary of. Changes in the formation of opposing players from the transfer window can make the opposing team better. So, Napoli must be careful and maintain the physical and mental players in order to continue to appear consistent after this break.