And Spanish publication Diario Gol claim Raiola is now offering the 18-year-old's services to United - giving them the chance to sign him ahead of Madrid.
Donnarumma, who one year left on his current contract, has informed Milan that he will not be signing a new deal with the club.
"We were taken by surprise, as we had confidently hoped Donnarumma would be the goalkeeper taking Milan into the future that we could build the team around".
"We wanted to make him a symbol of Milan for our fans and Gigio had everything required to fill that role", he added.
"Right now, you see some insane figures being mentioned on the transfer market".
About $4 million raised for London fire victims
Every family whose home was destroyed in the Grenfell Tower fire will receive a down-payment of at least £5,500 on Monday. The 91-year-old monarch said it is "difficult to escape a very somber mood" on what is normally a day of celebration.
According to Gianluca Di Marzio, there were further talks between Milan and Perin's agent on Sunday, with the former ready to offer €7m plus bonuses to prise him away from Genoa.
"I have no problem with Fassone and do not intend to wage war with Milan, but in these circumstances, I don't see how the situation can be resolved".
It is suspected that Raiola's comments are in relation to the fact that Milan postponed renewal discussions until the new ownership was in place, and then requested a response from Donnarumma within a fortnight.
The 18-year-old goalkeeper is regarded as the heir apparent to Gianluigi Buffon with the Italy national side having produced a string of impressive performances in his fledgling career. "They told us to make a decision by June 13, so we did".