On-loan Marseille midfielder Joey Barton was involved in a heated exchange with former Germany international Dietmar Hamann on Twitter on Monday night.
Barton, who is known for his outspoken nature on the social media platform, had recently said that l'OM forward Loic Remy was heading to his ex-club Newcastle United during the current transfer window.
Recent reports, however, have suggested the Frenchman could in fact join Queens Park Rangers, despite their manager Harry Redknapp saying last week that he had been snubbed by the striker.
Reacting to the speculation, Barton, who is on loan at Marseille from QPR, suggested that Newcastle potentially missing out on Remy was down to the club's managing director Derek Llambias.
This claim evoked a reaction from Hamann, who played alongside Barton at City in the 2006-07 season, with the German suggesting the Englishman should stay out of "club politics".
Then followed a lengthy exchange between the pair, which ultimately turned into a slanging match, with Barton writing that Hamann should "get his own life in order first" and labelling him "Tourette's face".
Hamann issued a retort to the "England international", who has one cap to his name. He wrote on Twitter: "No problem Joseph let's see each other in 5 years I hope I don't have to go to Walton #prison."
He added: "The medals won't make my kids respect me but im (sic) not prepared to punch a child in the face in McDonald's for them to respect me."
Barton also wrote: "Sick of washed up former pro's giving it big portions cos (sic) they've wasted their money. Medals don't pay your kids schools fees... #jogon."
On Tuesday morning, Barton issued an apology via his Twitter account: "I've slept on it. I have no right to question a man I hardly know. I must, therefore apologise for my part in last nights (sic) heated exchange."