PSG are willing to meet the €222 million release clause to sign the Brazilian attacker, who is interested in leaving Camp Nou to increase his chances of winning the Ballon d'Or.
However, Barca president Josep Maria Bartomeu and technical secretary Robert Fernandez have stated, however, that UEFA's Financial Fair Play rules would make it impossible for any club to meet the release clause.
While the 25-year-old remains silent on the matter, Mascherano urged him to stay with Ernesto Valverde's for the new La Liga season.
"Obviously he is young and I hope he's here with Barcelona for many more years," the Argentina defender said to ESPN.
"He is a really important player for the club. Because of his age, he's the future of the club and we hope we can keep on counting on him.
"He's accustomed to the pressure and people talking. There's always going to be rumours and news around him.
"It's really difficult to give advice. Firstly, I'm not anyone to be giving advice and secondly, I see him really happy here, really happy. [Barca] are a club that have made it possible for him to perform at his best. But after that, each person has to make their own decisions."