Joey Barton has apologised "unreservedly" for his part in a heated discussion about Rangers' 5-1 defeat to Celtic that led to him being banned from the club's training ground.
Barton was in the team that was swept aside in the Old Firm derby at Celtic Park and he revealed on Twitter that a "full and frank" discussion regarding the embarrassing result took place at Rangers' Murray Park training ground on Tuesday.
The former Manchester City and Newcastle United midfielder confirmed that Rangers manager Mark Warburton has asked him not to return to training until Monday, and the 34-year-old is expected to play no part in the club's game against Ross County on Saturday.
In a series of tweets, Barton said: "After the Old Firm game on Saturday everybody was hurting and in training on Tuesday there was a full and frank discussion about the result and reasons for our loss.
"The discussion we had involved some sharp disagreement about the game and some harsh words were said. There were only words involved in the disagreement, nothing else.
"Nevertheless, some of the words used did overstep the mark. I accept that some of the things I said were inappropriate and for that I apologise unreservedly."
Barton has featured in all five of Rangers' Scottish Premier League games this season, of which they have won two, drawn two and lost one.
He added: "The manager felt that my words were inappropriate and asked that I take some time out to reflect on what was said. He judged that it was best if I didn't report for training again until Monday.
"Whilst I don't feel this was necessary, I fully respect the manager's decision."
While he stopped short of naming other players involved in the incident, Barton added in a Tweet that was later deleted: "Apologising doesn't always mean that you're wrong and the other person is right.
"It means you value your relationship more than your ego."