The striker faces more competition at City following the deal for Dzeko.
But asked if his client is worried about the arrival of the former Wolfsburg striker, Mino Raiola said: "The more strikers the better it is. Mario enjoys himself this way. He likes to have fun so there is no problem.
"He isn't thinking about being afraid if Dzeko or Messi or the others come in.
"He believes that he is a strong player. He believes in his chances.
"Mario is happy at the moment. My advice is to stay in England."