Barton left Manchester City, where he began his career, in a £5.8m move this summer. During his time in Manchester the tough-tackling midfielder saw loads of controversy, but Stuart Pearce said Barton's training ground bust up was the end of the road.
The two fell out after Barton allegedly assaulted team-mate Ousmane Dabo in a training ground confrontation, which the former England skipper saw as the last straw.
Pearce (who had by then been sacked as manager): "If I was in charge, I'd have done the same on the grounds that I don't think the dressing room would have accepted him any more."
Barton: "I didn't speak to him about moving to Newcastle. We had a relationship breakdown in the end and he came out and said certain things I think he shouldn't have said.
"There's a lot of things I feel about him but I've not come out and said them and I don't plan on doing so. When you have a working relationship with someone there's a lot of things that should be kept in-house. Stuart thinks different and he's entitled to his opinion but if everyone spoke their opinions we'd have anarchy and chaos in this world."
Barton spoke of his move to Newcastle:"I'm an Englishman and nothing makes me more proud than to play for my country. I'm very patriotic.