Bernardo Silva has expressed regret at any offence his tweet may have unintentionally caused.
The Manchester City man has written a letter to the Football Association as part of the club’s observations on the message he sent.
The club responded ahead of yesterday’s 5pm deadline, and must now wait to see whether the FA will take it any further.
If charged, Bernardo could face up to a six-match ban.
He said any offence was not meant, but that he had learned his lesson from the matter and there would be no repeat.
Benjamin Mendy , who was the subject of the joke, has also written to the FA to support his friend and make it plain that he took no offence.
The letters both players have sent remain confidential, but City sources say that Bernardo regrets the tweet and will not be repeating his mistake.
He sent a tweet to Mendy which contained a picture of the City left back as a child, and compared it to a caricature of an African child which is used to advertise a popular Spanish snack.
The FA are also thought to be investigating a video in which Bernardo describes Mendy as "naked" because he is wearing a black T-shirt and shorts.
A Kick It Out statement had said: “Racist stereotypes are never acceptable as 'banter', and we're shocked that someone who is a role model to millions has failed to understand the discriminatory nature of his post.
“The FA has been notified and we believe that retrospective action should be taken, including mandatory education - which is vital to challenge offensive behaviour such as this.”
The FA followed that by inviting the club to make their observations, and all the evidence examined by the FA’s disciplinary department to decide whether any more action needs to be taken.
