The Queens Park Rangers defender and former England international Rio Ferdinand has been charged with misconduct over a comment he made on social media site Twitter.
The Football Association hasn't identified the posting in question, but reports suggest it concerns a tweet in which Ferdinand had referred to the mother of another Twitter user as a "sket", a derogatory slang term for a promiscuous woman.
A Twitter user provoked the tweet that appears to have landed Ferdinand in hot water by sending him a teasing message on transfer deadline day that said: "Maybe QPR will sign a good CB (centre-back) they need one."
Ferdinand replied: "get ya mum in, plays the field well son! .sket."
The former Manchester United defender, who won 81 caps for England, is a member of a commission set up by FA chairman Greg Dyke to investigate how to improve English football.
Ferdinand has six million followers on Twitter and is a prolific user of the social networking website.
However it pales in comparison to the social media profile of Real Madrid star Cristiano Ronaldo who's become the first athlete to have 100 million Facebook followers.
This puts him nearly 30 million fans in front of Barcelona's Lionel Messi, his rival for world number one footballer.
Of Ronaldo followers, 78% are men and 22% are women and are most commonly called Luis, Mohamed, Ali, Jose and Maria.
They mainly come from Brazil, Indonesia, India, Mexico and the United States.
The commercial power of Ronaldo, who also has 30.5 million Twitter followers, was demonstrated when he posted six messages over two days advertising the Tag Heuer watch brand.
These received 34.9 million Facebook hits and 2.4 million likes, which the watch company values at $600,000.
Ronaldo's former Manchester United team-mate Wayne Rooney earlier this month became the first Premier League footballer to reach 10 million followers on Twitter.