Lucca was on-loan at Napoli from Udinese this season before the Azzurri took up his permanent option and sent him on-loan to Nottingham Forest last month with an option to buy.
Nani told TMW: "I think it's just a matter of time. He went to the Premier League, which is one of the best leagues. I'm sure he'll find a way to succeed; he has all the right qualities.
"You don't get to the national team by chance."
Nani also discussed burning off AC Milan and Inter to land Branimir Mlacic from Hajduk Split.
He added, “I didn't go to the beach (in Croatia), but I tried to get close and start negotiations in person. Things are often resolved more easily in person.
"The deal had become complicated because the boy had attracted huge clubs. We left, and it was easier to close the deal there.
"He was our primary target, and we got him. These are Udinese-style deals.”