He admitted the Italian has failed to speak to him this summer.
Johnson said: "I have not had much contact from the club. It has been like that for quite a few of the players.
"It had been arranged at the end of last season that I needed to go out and get first-team football."
Johnson admits he has a point to prove after becoming a forgotten man at the Etihad Stadium.
"Hopefully the injuries are all behind me now," he said. "I believe I can go even higher than I was before."