Prestianni is a 16-year-old winger who was first linked with Real Madrid in November last year, and has since attracted admiring glances from many top European outfits.
However, the right-footed Prestianni, who operates off the left wing and likes to cut inside, now appears to be heading for Barcelona.
"Barcelona is going to pay the clause for Prestianni. 3 million-dollar sales for Vélez, Perrone, Orellano and Prestianni," said Hablemos de Velez TV (via Sport).
The Catalans are also closing in on 18-year-old Lucas Roman, who plays as a winger or attacking midfielder.
It's been reported that Barca have already completed the signing for €1.2million.
"A winger or attacking midfielder, he is a very fast, skilful player who has a great shot from outside the area," said former Barca youth coach Oscar Hernandez Romero of Roman, on Cadena SER (via MD).
Roman has already been selected for Argentina's U-20 national team, coached by Javier Mascherano.