The City boss says there is a chance Johnson may be allowed to leave before the transfer window.
He said: "Adam is a very good young player who wants to play football. I understand this so if we can find a solution for him in the next ten days or so, we will.
"It is difficult for him and I understand his situation and are talking to him about it at the moment, but if he stays with us, that is fine, too. We will have to see what happens."