Gianluigi Donnarumma
Donnarumma is set to leave his boyhood club after rejecting a new deal. Reuters

Manchester United's chances of keeping goalkeeper David de Gea have increased substantially after it was revealedReal Madrid target Gianluigi Donnarumma has opted against committing his future to AC Milan.

Despite stating his desire to remain at the San Siro just a few days ago, Milan chief executive Marco Fassone confirmed on Thursday (15 June) that Donnarumma's agent Mino Raiola informed the club of his client's decision to reject a contract offer believed to be worth £3.9m (€4.5m) a year.

"[Mino] Raiola informed us that Donnarumma has made a definitive decision not to renew the contract with Milan," said Rossoneri CEO Fassone said at a press conference.

"I want to remind you all that 10 days ago [director Massimiliano] Mirabelli made a significant contract proposal to the player, one even bigger than the reports that appeared in the various papers.

"The player evaluated it and made some evaluations that were not just economic, but he told us that he does not wish to renew the contract and his time with Milan will therefore conclude by 30 June 2018.

"We were taken by surprise, as we had hoped Donnarumma would be the goalkeeper taking Milan into the future, that we could build the team around. Naturally, the decision leaves a bitter taste in the mouth, but now we have to go forward."

David de Gea
De Gea has been heavily linked with a move to Real Madrid Getty

The Italian giants' encouraging start to the summer transfer window has been dealt a major blow and they now face a tricky decision regarding the prodigious 18-year-old. Milan could force Donnarumma to see out the final year of his contract and risk losing him for nothing, or cut their losses and sell the esteemed wunderkind for a fee that would still not befit his true value, due to the lack of time remaining on his deal.

It was reported earlier this month that Real Madrid were preparing to end their interest in Manchester United's De Gea, with Los Blancos boss Zinedine Zidane keen to stick with Keylor Navas for one more season before making a move for Donnarumma, who would be available for free next summer. Raiola is believed to have offered Donnarumma to Real Madrid officials.

Los Merengues have tracked De Gea for a number of years and came very close to signing the Manchester United stopper in the summer of 2015, but a bizarre administrative error put paid to the Spain international's proposed move back to the Madrid.

De Gea has developed into one of the best goalkeepers in the world since signing for Manchester United six years ago and has two years left on his current contract at Old Trafford.