#1 Matthijs de Ligt
de Ligt is currently one of the best center-backs in world football and he is only 19 years old. The Holland international is a player who will fit seamlessly into the Barcelona system as he has the technical ability of a midfielder and he loves to get on the ball.
The 19-year-old is a leader on the pitch and he can be the long term replacement of Gerard Pique as the Spaniard is entering the latter phases of his career. de Ligt is on the wish list of many big clubs in Europe and will not come cheaply for Barcelona.
The Holland International can turn out to be a brilliant signing as he has all the traits you look for in a world class player. If signed, de Ligt has the potential to be Barcelona's rock for at least 10-15 years. If the rumors are to be believed, Barcelona are thoroughly interested in his services.