Mantovani was in charge of Napoli's scouting division for 11 years and recalled how close they came to signing the Norway ace.
He told Radio Napoli Centrale: "Yes, we had the Norwegian, as the president said. It is a deal that other clubs closed and with other figures, but we were always looking for all the ideal players for us."
Mantovani also insisted the appointment of Rafa Benitez in 2013 was key to the club's rise.
He remarked: “We had a meeting in London to sign him. Mazzarri's Napoli, with Lavezzi, Cavani and Hamsik, was already very good, but Rafa gave us the awareness of being a team that can always be among the greats.
":Playing in the Champions League, starting with Benítez, became something natural. Being so international, signing players from Madrid, makes you take a leap forward and makes you feel like a top club. We went to play matches that we would never have imagined, speaking the same language as the clubs that play in the Champions League every year.”