The Italy forward has until 6pm on Friday to respond to the Football Association, which has asked him for an explanation, before a decision will be made whether to charge him.
Balotelli, 24, had reposted an image from the computer game Super Mario on his Instagram page with the heading "Don't be a racist".
The text then read: "Be like Mario
He's an Italian plumber, created by Japanese people, who speaks English and looks like a Mexican" and went on to describe a black man and a Jewish person.
After people criticised the post, he deleted it before writing on his Twitter account that his mother was Jewish
And he issued a statement to apologise, explaining he was trying to be "anti-racist with humour".
Ged Grebby from Show Racism the Red Card (SRtRC), an educational charity which uses football to promote an anti-racism message, was encouraged by Balotelli's immediate apology.
That was in contrast to other senior figures in football who have been criticised for making racist remarks recently, but who had not fully apologised, he said.
Mr Grebby, who is the campaign's chief executive, said: "I think it says something about Mario that he had the decency to do that."
Mr Grebby said the charity condemned Balotelli's deleted post, and said it could not be justified.
But a major message of SRtRC was to get people to recognise their own racist behaviour, to admit it and then to change.
"With Mario, almost immediately, he deleted the post he had done, recognised his mistake and said sorry," Mr Grebby said.
Source: PA