Morata, who scored in Chelsea’s 2-1 victory, tweeted after the game: "Since I arrived, I have been able to feel your support every single day, you are amazing and I'd like to ask you to please respect everyone!"
Kick It Out, which campaigns against racism in football, called for the fans who sang the song to be banned.
In a statement, the organisation said: "There is no place for such disgusting chants at football matches and in wider society".
"Kick It Out welcomes the clear statement by Chelsea FC, deploring the chants and asking all supporters to cease repeating the chant.
"The organisation expects Chelsea FC to ban any supporters who are identified as indulging in such abusive conduct and expects the police to take action against any identified perpetrators."
