AC Milan's Gianluigi Donnarumma must decide on his future - Fassone

AC Milan cannot wait too long for Gianluigi Donnarumma to decide if he wants to stay at the club, according to general manager Marco Fassone.

Donnarumma's Milan contract still has a year left to run on it, but if he chooses not to extend that deal the club are likely to try to sell him this summer while they can still seek a sizeable transfer fee.

Fassone does not want the issue to drag on all summer, though, and he has told the 18-year-old goalkeeper, who has been linked with some of Europe's top clubs, that he must make up his mind quickly.

"Donnarumma is a cornerstone, a pillar, a foundation for next season and we told him this the first time we met for talks," Fassone told Mediaset. "We've been telling him that now for 45 days. I can see in his eyes that light, that willingness to stay and do great things with this Milan, but what we cannot do is wait.

"We need to give [coach Vincenzo] Montella his squad for next season on July 3. Our time is more pressing than [Donnarumma's agent Mino] Raiola's. We need to know if we have a goalkeeper, if we don't have him or if we have him with his contract expiring. There hasn't been any meeting yet.

"As you can easily imagine, no club would leave a goalkeeper like Donnarumma in the stands, but we cannot have a goalkeeper at Milan whose contract is expiring. But I'm confident. We need to have a plan B in case things don't go the way we hope, but I am convinced that our offer and our plans for him are good. If the answer were still to be negative, then we would have to accept it and activate plan B."

Fassone also said that the club intend to build their future around coach Montella.

"Things are working really well with Vincenzo," he told Sky Sport Italia. "He's a great technician on the field. He's our coach and certainly he'll be our coach next year. I'm convinced he will be the coach who leads us to the top again."

There is not the same certainty about whether Carlos Bacca will report for training in July.

Bacca missed a penalty in the 2-1 loss to Cagliari on Sunday and appeared distracted by the rumours surrounding his future, although Montella says that should not have got to him.

"He's at an age now where he's no longer a young lad who could let transfer speculation affect him," Montella told Mediaset. "I could have done more for him as his coach and he could have done more too.

"Both of us have always wanted to do the best we could, even if neither of us have succeeded. He's a great player, though, and I'm happy to coach him."