Maurizio Sarri slammed "stupid people" for tarnishing the reputation of Chelsea fans after new allegations of anti-Semitic chanting emerged from the win at Watford.
A small section of travelling Blues supporters were reportedly heard singing a racist song at Vicarage Road on Wednesday.
The club earlier this month condemned the "abhorrent" acts of individuals who allegedly voiced anti-Semitic sentiments during the Europa League trip to Hungarian side Vidi.
Sarri criticised the offending individuals but claimed the behaviour was not indicative of the club's broader supporter base.
"I didn't hear anything. But I think first of all I want to speak with my club. Second, I don't want to generalise," the Italian told reporters.
"For the 99 per cent of cases, our fans are very good, are wonderful. Then in every community I think there are some stupid [people].
"Altogether we have to fight against the stupid people, but not against the Chelsea fans."
The Vidi incident came five days after the club and Metropolitan Police launched investigations into allegations that Manchester City forward Raheem Sterling was racially abused in a Premier League match at Stamford Bridge.
