The former Benfica stopper told Record: "They're two great players.
"They are new and will have to go through a phase of adaptation to English football, which really is completely different from that played in Portugal. But they will do well at United.
"We saw what happened with Cristiano Ronaldo, who has been extremely well supported since he arrived in Manchester, and has become one of the best players in the world in those three or four years. With Nani and Anderson, the same thing can happen, without any doubt."