Neymar, 28, signed for PSG from Barcelona in 2017 for a world record €222 million transfer fee and has won three consecutive league titles in the French capital.
The forward was close to rejoining Barcelona last summer and former Brazil international Juninho said that Neymar needs to show the club more respect.
"Look at Neymar," he told the Guardian. "He moved to PSG just because of money. PSG gave everything to him, everything he wanted, and now he wants to leave before the end of his contract.
"But now is the time to give back, to show gratitude. It's an exchange, you see. Neymar needs to give everything he can on the pitch, to show total dedication, responsibility and leadership.
"The problem is that the establishment in Brazil has a culture of greed and always want more money. This is what we were taught and what we learned."
PSG's Leonardo responded and urged the Lyon board to focus on their own club.
"I don't understand why Aulas talks so much about PSG, and Juninho now talks about PSG and Neymar," he told RMC Sport. "It would be better to talk about their club.
"We are not talking about Lyon's situation and I ask OL not to talk about our players and our club."
PSG are preparing to return to action when they face Saint-Etienne in the French Cup final on July 24.