According to The Sun, Ronaldo has told his close friends that he is expecting to add to his family "very soon", seven years after the birth of his only other child.
Cristiano Jr was born in 2010, also understood to be through a surrogate, though the identity of the mother has never been revealed.
A source is quoted by the publication as saying: "He feels the time is right for his boy to have brothers to grow up with. Cristiano and his family can't wait to meet the new members of their clan.
"He likes to keep a tight lid on his private life but has told loved ones and close friends the baby boys are due to arrive very soon."
Ronaldo is currently in a relationship with model Georgina Rodriguez.