Flitcroft has admitted that selling Stones was "like losing a member of your own family".
He said: "On Wednesday, I was pretty confident that we would keep John.
"But then I got a call on Thursday morning to say that he would probably be leaving. To be honest, I am numb. It is like losing a member of your own family. I was asked if I could replace him, and the answer was 'No.' How do you replace the best young defender in England?
"There is nobody out there as good as John, and that is why clubs were prepared to pay £3million for him."