Ferrer was the assistant to former PSG sporting director Antero Henrique and has lifted the lid on Cavani's time with the Parisians.
Portuguese Henrique spent three years with PSG before leaving in 2019 after being replaced by current sporting director Leonardo. And working alongside Henrique was Ferrer.
On Cavani, Ferrer told Le Parisien via Le 10 Sport: “Cavani is an atypical player, I don't know another like him. He had to do only two evenings during his entire adventure in Paris. He has never succumbed to the glamorous side of the capital. No human being can do that."
Ferrer insists Cavani's anger over the way he was treated in the final months of his time with PSG was understandable. The centre-forward was allowed to come off contract by PSG sporting director Leonardo, which eventually saw him skip the club's Champions League knockout campaign in Lisbon.
Ferrer continued: "His life is football, 100%. He was terribly disappointed with how it all ended. That's why he chose not to play in Final 8 (of the Champions League), it wasn't about money.
"Myself, I thought he was going to play in it. But he was so disappointed that he couldn't. It was a strong choice."
Cavani signed a new contract with Manchester United last week, which will run to the end of the 2021/22 season.
A recruitment specialist, Ferrer, meanwhile, resigned from PSG in December.
- updated May 17