Neymar swapped Barca for PSG in a world-record €222million transfer in 2017 but the Brazilian superstar has been regularly linked with a Camp Nou comeback.
The 28-year-old forward spent four years at Barca, where he won two LaLiga titles and the Champions League among other honours.
Mascherano was team-mates with Neymar when Barca claimed the 2014-15 Champions League trophy via a 3-1 win over Juventus in Berlin and the ex-Argentina captain reflected on that successful night at Olympiastadion.
"The other day, I watched the final in Berlin again and what the three up front created was impressive, Neymar, Suarez and Messi," Mascherano told RAC1.
"Each of them had a position in the team, the pressure after losing the ball and control.
"They added a lethal edge to our play. I hope Ney returns to Barcelona and they play together. It would be so nice for the club and the fans."