Chelsea have called upon fans to stop singing a song about striker Alvaro Morata that contains an anti-Semitic reference.
The Spain international opened the scoring as the Blues defeated Leicester 2-1 away from home on Saturday, prompting the chant that the club has called to end.
"The language in that song is not acceptable at all. Alvaro has requested supporters stop singing it," a spokesman said.
"The club and the players appreciate the fans' passionate support away from home, of course, but the language in that song is not acceptable at all.
"I've spoken to Alvaro about it. Alvaro does not want to be connected with that particular song in any way and both the player and club request the supporters stop singing it with immediate effect."
The former Real Madrid forward also called for respect to be shown in a post on his official Twitter account.
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! — Álvaro Morata (@AlvaroMorata) September 9, 2017
He wrote: "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!"
Anti-racism football campaign group Kick It Out welcomed Chelsea's response, calling for the club to take action against supporters "identified as indulging in such abusive conduct".
A statement read: "Kick It Out is aware of alleged antisemitic chanting by supporters of Chelsea FC in their Premier League fixture at Leicester City.
"Kick It Out condemns the alleged chanting by some of Chelsea’s supporters during the match at the King Power Stadium. 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."
Morata has made a strong start to his time in the Premier League, scoring three goals in his first four outings, having missed a penalty in the Community Shield against Arsenal at the beginning of August.
Antonio Conte was delighted to see him hit the back of the net again, but his link-up play was the most pleasing aspect for the head coach.
"It is a good day for the team and for Alvaro," said Conte in his post-match press conference.
"It is always important for a striker to score. It is important to see he is improving and always more involved in our idea of football.
"That is most important and if he scores then I am very happy."
Chelsea are third following their victory and Morata has his eyes set on displacing Manchester United and Manchester City to take top spot.
"It is important to win here. Always against Leicester at this stadium it is very difficult to win," Morata told Sky Sports.
"We were in a good position at 2-0 but suffered to the end. This is the Premier League.
"I am good but the most important thing is we are not in the first places and we look forward to moving ahead in the table."