McCarthy said: "It's right what James Harper has said. I did think there would be an issue over his fitness, I did go and watch him play after that - and he played very well.
"But if I am going to make a mistake, I'd rather make it at this stage than when we have taken him on contract and he is not available to us. Such is life in the big city.
"If the lad wants to prove me wrong, good luck to him. I've no problem with that. Will I re-visit it? Put it like this - there's a darn sight less chance now that he has gone public over what I consider to be private and confidential discussions.
"You should do your talking on the pitch and not through the newspapers."