The 21-year-old has long been linked with a move to City. The Blues have managed to agree on a £10.46million deal with Hamburg for the defender.
“I am going to sign on (for City) before leaving for the World Cup and the deal will be completed,” Boateng told Bild magazine
“It has been decided that I am moving there.”
“He (Mancini) came with two representatives to Hamburg and we chatted for one or two hours,” said Boateng.
“He convinced me to make the transfer. He believes that I will definitely need a few months to get settled in once in England, but that he sees so much potential in me that he will improve me.
“Even if many people say that I am going to struggle to make the breakthrough, I am confident that I will.
“I am not afraid of anybody.”