​Gianluigi Donnarumma has received support from Manchester United midfielder Paul Pogba after rejecting a new contract from AC Milan.

The Italy international, currently on duty with the country's Under-21 side, has put Europe's top clubs on red alert after failing to agree a new deal with Milan, with Juventus, Manchester United, PSG and Real Madrid all said to be interested in the 18-year-old.

The teenager was targeted by Italy fans during the Under-21 match against Denmark as supporters threw fake money onto the pitch but Pogba has tweeted a message of support to Donnarumma.

He posted: "Donnarumma soon best in the world deserves only respect for all he's done until now"

Marco Fassone recently confirmed Donnarumma's intention to leave the club, as quoted by ​the Guardian“We are disheartened. [Donnarumma’s agent] Mino Raiola has conveyed to me Donnarumma’s decision not to renew. It’s his final decision.

“In the past few days, sporting director Massimiliano Mirabelli [the club’s director of sport] made a very big offer to the player, who evaluated it and today he informed us that he did not intend to renew.

“We were confident that Gigio would be the goalkeeper of this new Milan; a pillar upon which we would build, but now we have to re-evaluate everything.

“This decision, taken by the player and his agent, is disappointing, but we have to move on; Milan move on.”

Whether Donnarumma will be Milan's first choice goalkeeper next season remains to be seen with his future in doubt following the contract rejection.