Despite the speculation, Neymar started Barca's International Champions Cup match against Juventus on Saturday and scored two exceptional goals in the 2-1 victory.
Speaking afterwards, Marlon voiced his confidence that his compatriot will stay at Camp Nou.
"For me, Neymar is one of the best players in the world. I haven't spoken with him but I hope he stays," he said, as quoted by Catalan publication Sport.
"He's our team-mate and one of the best. We want him to stay with us.
"We don't need to convince Neymar to stay. He's here with us and he's going to stay."
Midfielder Sergi Samper says Neymar has offered no indication that he wants to leave, despite some reports in Spain suggesting he has already informed his team-mates of the move.
"Neymar will stay. He looks relaxed and he hasn't given any hints that he wants to go," he said.
Neymar's father and agent is said to have met with PSG officials on Sunday in the United States to discuss the terms of the player's potential deal.
Meanwhile, Sport have reported team-mates Lionel Messi and Luis Suarez spoke at length with Neymar on Saturday evening at the Sheraton Hotel in New Jersey, trying to convince him to stay.
It is claimed the former Santos star was won over by his strike partners, although he has yet to make a public declaration over his plans.