Napoli president Aurelio de Laurentiis confirmed the bid yesterday.
"I contacted Unicredit directly for Lamela and Marquinhos. I offered them 40million euros (£34.1m)," he told Football Italia.
"Instead, they offered me the services of Pablo Daniel Osvaldo at all costs, but seeing as we have Edinson Cavani right now, we don't need him.
"However, at this moment in time, I'm no longer convinced by Lamela and Marquinhos. I've noted that there are other strong players around who are cheaper."