It was a humiliating defeat for Napoli. But I think in that match Napoli only fielded second-string players and there were several main players. It seems that Napoli is focused on improving their ranking in the League and playing well in the Champions League. However, losing by 4 goals like this is still quite embarrassing. Because if the reason is for the Champions League then the next match schedule is still very long away. Is this bad performance because Napoli don't really care about this match?
Yes, this can be said so because they lost without any reply to Napoli at home.
Almost most of the big Serie A teams when they play in the Coppa Italia they always lower these second layer players do not want to take excessive risks on players so that more are rested.
Even though the Champion League is still long with a time lag while Serie A still continues every week, Napoli may consider Serie A more important than the Coppa Italia.
As far as I'm concerned, when they play in the Coppa Italia these top teams are more likely to get bad results. Although in the end only the top teams managed to win the trophy, but those teams are also the ones that really have good stability also in Serie A at least . Therefore, despite Napoli have big loss by Frosinone but ya, I personally wasn't surprised by that result because it's a common occurrence for events like this.
Ofcourse, it would be a different judgment if a top Serie A team lost big like that for a match in Serie A and if the result is like that, then of course it would be a very bad judgment . But ya,as long as the top teams are still losing within a normal score, then atleast their considerations will also remain fine and will probably still be on track as well.