Celtic goalkeeper Artur Boruc is remaining coy on his training ground bust-up with team-mate Aiden McGeady.
The duo were involved in an altercation last week with reports suggesting the pair came to blows.
McGeady has been sporting a black eye, but Boruc claims he does not know what caused his team-mate's injury.
"I don't know where the bruise came from," Boruc told the Scottish Sun.
"It's not a subject for discussion."
Boruc has endured a difficult time on and off the field at Celtic this season, with the keeper making a number of high-profile mistakes.
The Polish international has played down the furore over his dip in form and is confident of getting back to his best soon.
"Everyone has different moments and everyone has to get through the worst ones," added Boruc. "It's only football. We make mistakes like everyone. It may be due to a lack of concentration sometimes.
"It has grown into hysteria. There is nothing to talk about - everyone makes mistakes.
"I just have to train hard. That is all I can do.
"But I hope I will grow to better form that I showed at Euro 2008."