Cavani climbed off the bench in the second half, with Manchester United two goals down at the Saint Mary’s stadium and the former Paris Saint Germain striker underlined his status as one of Europe’s most lethal frontmen despite his advancing years with an assist and a brace to take Ole Gunnar Solskjaer’s men beyond the Saints.
The 33-year-old received several congratulatory messages on social media after the game, but he used the phrase ‘gracias negrito’, a term with a racial connotation in England, to appreciate one from a friend.
Cavani quickly deleted the message after he was made aware of its implications in England but the Football Association had already taken note and have launched an investigation, which could see the Uruguayan banned.
Cavani has apologised for the post and insists he meant no malice.
In a statement released by United, Cavani said: "The message I posted after the match on Sunday was intended as an affectionate greeting to a friend, thanking him for his congratulations after the game.
"The last thing I wanted to do was cause offence to anyone. I am completely opposed to racism and deleted the message as soon as it was explained that it can be interpreted differently.
"I would like to sincerely apologise for this."
In a statement of their own, United added: "It is clear to us that there was absolutely no malicious intent behind Edinson's message and he deleted it as soon as he was informed that it could be misconstrued.
"Edinson has issued an apology for any unintentional offence caused. Manchester United and all of our players are fully committed to the fight against racism."