Alberti does not represent the Bosnian striker, but insists AC Milan agreed a deal with the Bundesliga side an the player in January.
“Milan have already signed Dzeko for June and he will arrive after the World Cup,” Alberti told Calciomercatonews.com.
“The deal was closed in January during an important dinner meeting between Adriano Galliani, Dzeko and the player’s father who works on his behalf.
“I can say that Dzeko is 100 per cent a Milan player. All that is missing is a signature on the contract and an official announcement.”