Andre Onana has rushed to the defence of team-mate Alejandro Garnacho after the youngster used gorilla emojis in a post about the goalkeeper.
The 19-year-old winger posted a photo of Manchester United's players mobbing Onana in celebration after he saved a decisive penalty in Tuesday's 1-0 win over FC Copenhagen.
Garnacho's post on X - formerly Twitter - featured two gorilla emojis, without any words.
The post, released just after midnight on Wednesday morning, was initially tweaked via the edit function to remove the gorilla emojis, before the post was deleted entirely soon after. It was live for around 15 minutes.
The FA is aware of Garnacho's post and they could yet bring a charge against the player for offending behavior on social media - something Onana believes would be wrong.
'People cannot choose what I should be offended by,' Onana wrote on his Instagram story, using the same celebration photo used by Garnacho.
'I know exactly what @garnacho7 meant, power and strength.
'This matter should go no further.'
The FA have previously taken a hard line with posts made on social networking sites, bringing charges under FA Rule E3(1).
English football's governing body determine 'aggravating factors' under that rule to include comments that make a reference to any one or more of a person or persons' ethnic origin, colour, race, nationality, faith, gender, sexual orientation or disability.
While Garnacho's post has been deleted, under FA rules that does not guarantee an avoidance of retrospective punishment.
Manchester United have seen one of their players pulled up on their social media posts before.
Back in 2020, then-United striker Edinson Cavani was banned for three games and fined £100,000 for using the Spanish phrase 'Gracias negrito' - which translates as 'thanks little black' - below a friend's Instagram post.
In his native Uruguay it is a term of endearment, and not in any way offensive, but Cavani still deleted the comment and pleaded guilty to the FA charge.
In addition to his monetary and sporting punishments, Cavani was also made by the FA to undergo a two-hour face-to-face training course.
Twelve months earlier it was United's neighbours Manchester City that fell foul of players' social media rules when Bernardo Silva picked up a one game ban.
Silva was banned for a game and fined £50,000 for his Twitter post about then-team-mate Benjamin Mendy.
The midfielder chose to post an picture of Mendy as a child along with a cartoon character that is the symbol of Spanish chocolate brand Conguitos.
While the post was deleted inside an hour from when it was posted, Silva went on to show his bemusement at the negative reaction by writing: 'Can't even joke with a friend these days.'