Leonardo felt Mbappe was already planning to leave for Real Madrid at that stage.
"I was against (Mbappé's renewal), especially at the level it was done. Always. From the beginning," Leonardo insists about the large financial outlay had to made to keep Mbappé at the time.
"I even think he was supposed to be sold at the end of the 2020-2021 season, when PSG had an offer from Real Madrid and he only had one year left on his contract."
After the renewal, he left PSG due to differences with the board on the Kylian issue.
"How can this situation be managed? If you lose a player it's annoying, but the club is not going to die because of this. What great institution collapsed after losing a player? None. It may take time, but you always recover. I have been a player, but a footballer can never be more important than a club," he added.