England goalkeeper Fraser Forster does not know if he will still be at Celtic when they next play in Europe.
Norwich captain Sebastien Bassong has signed a new two-and-a-half-year contract.
The midfielder is alleged to have demanded a £3.5million pay-off to end his contract and push through a permanent switch to France.
However, Barton has taken to Twitter to play down the claims, insisting he has not had any such conversation with the club's hierarchy.
"A lot of rumours circulating about me, Marseille and QPR in last few days. As usual loads of #nonsense," he tweeted.
"I haven't had a conversation with anyone at QPR since February. When I told them Marseille had offered me 3 years. That was last I heard."
The 30-year-old impressed in his first season with L'OM, despite suffering several injuries in what turned out to be a frustrating campaign at times.
And Barton ended his discussion on the topic with a message for his current employer: "They know where I am if they want to talk."