Napoli captain Lorenzo Insigne snapped back at reporters after defeat to Cagliari.
A late Lucas Castro header proved the winner.
Sky Sport Italia pundit Giancarlo Marocchi angered Insigne when suggesting they played with the intensity of a pre-season friendly.
“I find that offensive, especially from a former player, to suggest that we didn't give our all out there," replied Insigne.
“You can criticise our results, but I will not stand for claims we gave less than 100 per cent today."