Reports claimed McGhee's training methods had come under fire from his disgruntled players, who have failed to win any of their last seven games.
The squad trained for the first time since the weekend on Tuesday morning and McGhee said: "The important thing for the supporters to know is that there was a really positive atmosphere and really positive attitude at training this morning.
"Anything they read about dissent or this business about criticism is absolutely rubbish.
"My reaction to what happened in the dressing room was not one of shock and we weren't slaughtered by the players.
"That is absolute ridiculous nonsense.
"We had a really constructive discussion, after which I was feeling much, much better than I did at the final whistle."
He added: "Some people have tried to put a spin on it this morning, that it was in some way critical of me and my methods, which is just not the case.
"There were some positive observations, some of which I had to go away and think, 'Right, OK, what do I do about that? What do I think about that?'
"But there was nothing offensive, nothing that I had any worries about."
The Dons boss is determined to win over his critics, telling RedTV: "Those who are mailing in support, I appreciate it and I thank them for that sincerely.
"Those that aren't, I just hope that eventually they'll realise that we're doing a good job and that we'll win them over."
He added: "I'm very focused and remain very determined about what I am doing here and what I came here to do."