The coach criticised his side for making a "serious error" that led to the only goal of the game as they lost 1-0 at home
Inter coach Stefano Pioli insisted the club are headed in the right direction after fans expressed their frustration during a 1-0 defeat at home to Napoli.
Jose Callejon's goal on the cusp of half-time was enough to earn Napoli a second Serie A victory over Inter this season, and Pioli's side are now without a win in their last six matches.
Supporters at San Siro displayed banners and voiced their dissatisfaction with Inter's downturn in form in recent weeks, but Pioli called for patience to allow Chinese owners Suning Holdings Group, who became the club's majority shareholders in 2016, to make the team competitive again.