The controversial midfielder was involved in a fight with two men outside Garlands nightclub in Liverpool city centre. A picture of the incident, apparently showing a shirtless Barton being held back by police and a woman, appeared on Twitter.
Merseyside Police confirmed two 21-year-olds were arrested at 5.30am, but Barton has decided not to press charges. The 29-year-old wrote on Twitter: "I got sucker punched in the back of the head. Not injured as reported just a small bruise on rear of head/ear. I've had worse. Life goes on! Thanks for the concern. Have a good day people."
He added: "Not planning on pressing charges as its not that serious. The police have also got better things to do with their time.
"Can I just say a public thanks to the police last night as they were and have been today brilliant."
QPR claim the two men hurled insults at the former Newcastle and Manchester City man before attacking him.
Rangers spokesman Ian Taylor said: "Joey Barton was involved in an incident in Liverpool city centre in the early hours of Monday morning.
"Barton was on his way home from a night out with his girlfriend when two men sang offensive chants and then proceeded to hit the Rs midfielder.
"Police were immediately on the scene and arrested one man.
"Barton decided not to press charges and left the scene with his girlfriend soon after. The club will be making no further comment."
Source: PA
Source: PA