QPR goalkeeper Julio Cesar has revealed the shot of him wearing a Chelsea shirt making the rounds on social media was part of a fancy dress costume for Brazilian team-mate David Luiz's birthday.
"I would like to clarify that last night I attended David Luiz's fancy dress birthday party and as a joke for my friend, my family and I dressed as him," Cesar said.
"I want to assure everyone that absolutely no offence was intended."
However, QPR are set to discipline the 'keeper, releasing a statement declaring the issue will be dealt with 'internally'.
Cesar donned the shirt of Rangers' fierce London rivals as he joined Luiz and other Stamford Bridge players for a party. His wife, Susana Werner, posted a picture of him in the shirt online.
The Brazil international goalkeeper moved to Loftus Road in the summer but has been unable to help lift QPR clear of relegation danger.
Only Reading are below Harry Redknapp's side in the Premier League, with relegation to the Championship now appearing a certainty.
QPR head of communications Ian Taylor wrote on Twitter: "The club is aware of an image of Julio Cesar circulating on social networking feeds.
"The image, which appeared on an instagram account, has since been deleted. The club will be dealing with this issue internally."