Racist abuse directed at Real Madrid's Vinicius Jr is a problem for the whole of Spanish football, says manager Carlo Ancelotti.
Mallorca fans were filmed allegedly racially abusing him during Sunday's 1-0 win over Real in La Liga.
"Vinicius is the victim of something that I don't understand. It must be solved," said Ancelotti.
"It seems that the problem is Vinicius, and it is not like that."
Real face Egyptian side Al Ahly in the Club World Cup semi-final on Wednesday in Rabat, Morocco.
In September some Atletico Madrid fans sang racist songs at Vinicius, which the club described as "unacceptable". Spanish prosecutors closed an investigation three months later, saying it was impossible to identify those responsible.
In December Vinicius said La Liga must act on racist supporters attending games, after he appeared to be abused during a 2-0 win at Real Valladolid.
La Liga said it filed charges to the "relevant judicial, administrative and sporting bodies".
Last month an effigy of Vinicius was hung from a bridge near Real's training ground. Spanish police are investigating a possible hate crime.
Neymar and other influential football figures defended Vinicius in September after a panellist on a Spanish football show compared his goal celebrations to a monkey.
Vinicius released a video statement in response to the "xenophobic and racist" insult, saying he "won't stop dancing" and "the happiness of a black Brazilian being successful in Europe bothers" many people.
Real midfielder Federico Valverde said: "On the issue of racism, that is people that are bitter with their own lives who go in the stands and try to pay for their frustrations with a 22-year-old kid. You have to have respect for other people."