On 3 January 2019, Naldo joined Ligue 1 club Monaco on a one-and-a-half-year deal. After the transfer was completed, Schalke 04’s executive manager Christian Heidel revealed that Manager Thierry Henry played a role to convince the player to join the club. However, his wife later criticised Schalke 04 on her social media account, for their poor treatment of Naldo. This prompted the club’s executive manager Christian Heidel to respond to her post, saying: "I don't read any posts, neither from our players nor their wives. I care what he says. And everything is fine."