Leonardo oversaw the deal in 2021 after it became clear Barcelona were allowing the Argentine to come off contract.
He recalled on RMC: "Messi wanted to stay at Barça, but from the moment Barcelona couldn’t keep him, PSG was the first choice.
"After that, there was a lot of misunderstanding. It was difficult for him. He had been in the same place for 20 years, and then you move. Saying he wasn’t happy is a way of defending himself. There was the elimination at Real Madrid; it was complicated."
Meanwhile, Leonardo admits he wanted to see Kylian Mbappe, now of Real Madrid, leave PSG in the same period.
He explained, "When he renewed his contract, he had conditions for staying, and I didn't agree. I couldn't stay. There were choices to be made. I would have said no sooner. Between Qatar and me, there has never been a problem.
“Would I have stayed if Mbappé had left? I don’t know if he had my head on his shoulders. It was a different perspective at one point.
"Because he wanted to leave. It wasn’t about money. He stayed because he’s a Parisian, but he wanted to go to Real Madrid. A player can never be bigger than the club."