The Brazilian, who has spent two seasons with the Ligue 1 outfit since his world-record transfer from the Blaugrana in 2017, has reportedly been made available for a move should the club receive a suitable offer.
Both former home Barca and key La Liga rivals Real Madrid have been linked with the forward, and Belletti, who played for the Catalan club between 2004 and 2007, has acknowledged that the Olympic gold medallist faces a major call over his next steps.
"A lot has been said about Neymar. I know hardly anything about this," the 43-year-old stated.
"For him, it is the moment to decide. He has to be very calm with his family to take the best decision."
However, such success has failed to materialise, with consecutive round-of-16 knockouts in 2018 and 2019 against Madrid and Manchester United curtailing their hopes of continental success.
PSG’s inability to challenge for such silverware has contributed to a difficult mood at the club that has seen Neymar reportedly clash with team-mates, leading to speculation that he will depart this transfer window.
Speaking on whether he would prefer a return to Camp Nou for the Selecao star or for Barca to make a move for outgoing Atletico Madrid forward Antoine Griezmann, Belletti admitted that his fellow countryman was his personal pick.
"I am Brazilian and I have played during all my life with the best Brazilian players of my generation: Ronaldinho, Ronaldo, Roberto Carlos, Rivaldo," he added.
"So, imagine, I am more about these kind of things."
A return to Catalonia could see Neymar link up with international compatriot Philippe Coutinho, who has struggled since making a big-money move from Liverpool, though Belletti believes his poor performances boil down to a lack of self-belief.
"When he gets more confidence, he will do much better,” he added.