Joey Barton was gagged by Marseille on Wednesday night after angering club chiefs by labelling Paris St Germain defender Thiago Silva an "overweight ladyboy" in an online tirade.
The midfielder, on loan from QPR, was ordered by Marseille officials to cease his attack on the Brazilian, which was also condemned by PSG and a prominent anti-homophobia group based in the French capital. Barton wrote a series of Twitter messages on Tuesday evening and Wednesday morning, in which he went as far as questioning whether Silva was "pre-op or post-op".
Marseille said in a statement that the club and Barton were keen to apologise for the midfielder's "inappropriate comments", adding: "The management asked Joey Barton to put an end to the attack on PSG's Brazilian defender. The Marseille midfielder pledged to immediately cease the posting of anything derogatory about Thiago Silva."
His outburst apparently stemmed from comments made by Silva ahead of PSG's Champions League quarter-final against Barcelona, when there was an oblique reference to Barton.
Silva spoke of an English Marseille player whose name he claimed to have forgotten that had taken to criticising big-name players including David Beckham because nobody was talking about him.
Barton made his initial "overweight ladyboy" remark following PSG's 2-2 draw with Barcelona, and on Wednesday morning added: "2 questions for Thiago Silva. Firstly, Why are YOU talking about ME, in your press conference before PSG v Barca? Very strange.
"Secondly, Are you Pre-Op or Post-Op? #transsexual #thiagosaladyboy. Baffles me, which way he's going. Is he a man changing to a woman or a woman changing to a man? Can't work it out."
The anti-homophobia group Paris Foot Gay said they had discussed Barton's comments with French league chiefs, and that they had been told he would be reported to the French Football Federation's national ethical council.
Reports from France on Wednesday night claimed that the FFF would not be taking the issue any further, after reviewing Barton's comments. Paris Foot Gay said that Barton's comments were "without doubt based on the stereotype linking Brazil to transexualism".
In a statement on their website, they added: "Paris Foot Gay considers this type of remark to be vulgar, discriminatory and funny to nobody and it should not be tolerated in someone with such a profile. To be a football idol excuses nothing and should, on the contrary, make players responsible for the impact of their remarks on the public (youngsters) especially."