#4 Gianluigi Donnarumma

It is hard to believe that Donnarumma is still 19 and has nearly made 100 appearances for the Rossoneri. He will certainly replace the retiring Buffon as Italy's No. 1 for years to come.
'Gigio' made his debut at the tender age of 16 and has established himself in the starting line-up ahead of more experienced keepers and has received a lot of praise from many pundits for his maturity and ability to cope with the pressure of being a the goalkeeper for a top side.
However, considering that AC Milan is in decline and hasn't won the league title for quite a while now, it will be interesting to see whether he will stay at the club or will move elsewhere.
Clubs like Manchester United and Chelsea may come for him if David de Gea and Thibaut Courtois decide to leave the clubs in the summer.
He may also be a long-term solution for Liverpool's goalkeeping problems, but Loris Karius is currently doing a commendable job at Anfield.