The Brazilian star has made it clear to PSG that he wants to leave the club and is reportedly keen on a return to La Liga, where he previously played for Barcelona.
Neymar moved to Paris in the summer of 2017 for a world record £200m but the 27-year-old has since found it hard to achieve anything other than domestic success in the French capital.
PSG have been knocked out at the last-16 stage of the Champions League in the two years Neymar has been with the club.
Neymar could still leave PSG this summer but a deal has yet to be agreed with Barca or Real Madrid, who have been linked with a big-money move for him throughout the summer.
But club president Leonardo believes his team’s star player hasn’t handled his transfer situation in the best possible way.
“Neymar has made mistakes,” he told RMC Sport.
“I didn’t know him before. Over time, I have got to know him.
“I honestly think he is a good boy with a very good heart. On the pitch, he is an extraordinary player.
Leonardo did dismiss reports, however, that Neymar was removed from training with the first-team squad by manager Thomas Tuchel.
“It’s wrong. He is not removed from the group,” he added.
“He follows his personalised rehabilitation program. He’s a Paris Saint-Germain player, he’s still in Paris for three years, so do not forget.
“We must analyse everything, we must fix everything before he can play again.”
Neymar has suffered with his fair share of injuries during his time with PSG, but Leonardo insists the attacker’s fifth metatarsal injury has completely healed up.
“Things are simple. He was handled by the best doctors and surgeons in the world,” he said.
“The treatment has completely healed Neymar’s fractured fifth metatarsal. His injury has completely been taken care of.”