"If Roy apologises now I will take his apology to my staff and my players, the people who were in the room when I was called an effing c*** and an effing w***** last week when I was told I couldn't coach or manage.
"I will see what they have to say and if the players back a return for Roy I will back them. There are no winners in this, no winners at all."
McCarthy denied that he had put a gun to the players' heads when they voted to carry on without Keane at a team meeting this morning.
"No, that wasn't the case. If the players want the situation reversed I will back them," insisted McCarthy.
FAI general secretary Brendan Menton revealed that the Association had been all but promised an apology from Keane in last night's interview.
He said: "We were led to believe that an apology would be forthcoming and would bring things forward.
"Sadly that was not the case and we need to move on now, we have a World Cup game in four days' time."
Players' spokesman Niall Quinn added: " I f Roy apologises I will welcome him and all the players will.
"We will sort out what he said about me in 30 seconds flat over a cup of tea."
It was Quinn who earlier admitted that he had tried to broker a peace deal between Keane and McCarthy.
The Sunderland striker also revealed McCarthy had given the players an ultimatum.
When asked if McCarthy had demanded the players chose between Keane or their manager, Quinn added: "You would have to ask Mick that, but you are not far from the truth."
Quinn went on to reveal how close Keane was to a comeback after he had brokered a deal with McCarthy, the players and Keane's advisor Michael Kennedy.
He said: "I still cannot believe that Roy did not apologise on television last night, as we were led to believe.
"I was desperate for Roy to come back, but he did not go any way to apologising and when we went into the team meeting this morning we had no choice but to back the manager and vote as we did.
"The vote was unanimous, all 22 were in favour of that statement, and it will become clear why when Mick McCarthy explains his position.
"I cannot say that Mick is to blame for this, Roy Keane is to blame for it. I had come so close to getting him back but Roy won't come down. He keeps saying he was right in what he said and did."
He went on: "As for the statement this morning, it should not have been released as quickly as it was.
"We had to start training quickly so the statement was released. It should have come after Mick's press conference so we are at fault there.
"We had to put it away to get people back to football."
Keane fails his screen test United fans back troubled skipper Quinn: I'm sorry I didn't stop him WORLD CUP - news and analysis Should Keane be allowed back?
