Chelsea have sent winger Kenedy home from their pre-season tour following the Brazilian's social media comments before a match in China.
The club had "solemnly and sincerely" apologised after fans accused the 21-year-old of xenophobia and racism.
He made the comments in Instagram posts before a 3-0 pre-season win over Arsenal, during which fans booed him.
Kenedy later apologised but will now play no further part in the tour and has returned to the UK.
The Football Association has written to Chelsea and has also asked the player to explain the comments.
He put two videos on Instagram, one featuring an expletive about China and another of a sleeping security guard with a phrase which translated as: "Wake up, China. You idiot."
In the wake of the incident, writing on social media, Kenedy said he was sorry if "someone was sad because I used an expression". He added it was "no racism, just an expression".
Chelsea said in a statement prior to him being sent home that the player, signed from Fluminense in 2015, had been "strongly reprimanded and disciplined".
"Kenedy's actions were a mistake that he will learn greatly from," they added. "His behaviour does not represent the entire team and does not align with our expectations and strict requirements of the young players."
On Sunday, Chelsea arrived in Singapore to prepare for the next match of their pre-season tour, against Bayern Munich at the National Stadium on Tuesday.