McCarthy sent home captain and star player Roy Keane last week after the Manchester United midfielder launched a verbal attack on his national manager.
Keane's dismissal from the squad has divided supporters and McCarthy has already turned down requests from Football Association of Ireland officials and even the Irish Prime Minister Bertie Ahern to reconsider his decision.
McCarthy told the Mail on Sunday: "There was no dignity and precious little respect in his choice of language.
"I have never witnessed such an attack from any human being.
"It was vicious and it was unjust. I looked at him as he waded in with one expletive after another and I asked myself if this was my captain; if this was one of my players.
"Was this a man who could serve Ireland as a role model for our kids, for the youngsters who dream of following him on to the World Cup stage?
"The answer to all of that, judging by his behaviour in front of all the other players and the backroom team, is no."
Players back up boss
McCarthy's parting shot at the Manchester United midfielder was: "Roy Keane is history now.
"He will never again get the chance to talk to me like he did last Thursday. No human being will talk to me like that again."
McCarthy has been given fulsome support from his squad, with Keane's former midfield colleague Matt Holland the latest to add his backing.
"Never have I witnessed such a foul-mouthed tirade as Keane subjected the manager Mick McCarthy to during that fateful team meeting," Holland wrote in his Independent on Sunday diary.
Keane had been his usual brooding self since our arrival in Saipan
"It started at 7.30pm and most of the players assumed it was about travel arrangements so we all sat around chatting, completely unaware of the volcanic eruption that Keane was going to inflict upon us.
"Keane refused to apologise for his comments. In fact he stood by them and then launched an abusive attack on the manager.
"It was absolutely extraordinary to listen to, and like the rest of the squad, I was stunned.
"McCarthy tried to appeal to Keane and reminded him of the times he had defended him in public or helped him, but Keane continued his barrage, leaving the manager absolutely no option but to send him home.
"Steve Staunton described it as "overstepping the mark", but that does not do it justice. Keane leapt over the mark in a way that would have done Bob Beamon proud.
"Now the saga's over there is a definite sense of relief at Keane's departure.
"He had been his usual brooding self since our arrival in Saipan. From the very start he moaned about well, everything really."