The Italian signed for Nice on deadline day.
“I'm very happy to have Mario with us and that he chose Nice," said Rivere in the player's official presentation.
“But I'd like to clarify a few things. It's been said that he's been offered everywhere, but in fact we sought him out. We contacted Mino Raiola, who is a great agent, a few weeks ago and asked for a striker.
“Mario was my idea, I kept refusing the other names he offered. He told me Mario wasn't possible but I asked to meet the player.
“I think meeting people is interesting. I'd been reading some positive things about him. When I met him we had, frankly, a very good time and I knew he was a good person.
“That's when I told myself, we have to try and sign him.
“The next day the Coach met Mario. He didn't know him and we were at the end of the market, so he told me it was difficult.
“But they spoke a long time, and though I'd never, ever sign a player if the Coach disagrees, we took him with great pleasure. We're aware of the risks.
“This is absolutely not a choice I took on my own. It would make no sense to do this without the collective consensus.
“Another thing I want to clear up. I've been reading about the monetary prize given to Mario, and the amount being talked of is absolutely false. I'd never comment on amounts like that for any player.
“Mario's contract is extremely secret. People can imagine whatever they like, but we know what we did and how. Unfortunately the information leaked to the Press is incorrect.
“Aside from the player, what I liked is that he told me it wasn't money that he was interested in. It's not an easy thing to say. He rejected more remunerative offers to come here.
“We know there is a risk, but we accept and we assume the risk."