Foot Mercato reporter Santi Aouna reported that Mastantono will sign a contract with Real Madrid for 6 years, with the contract term until June 2031.

reporters said that Mastantono will join Real Madrid immediately after the end of the Club World Cup. In this Club World Cup, River Plate is in the same group as Urawa Red Diamonds, Monterrey and Inter Milan, and Real Madrid is in the same group as Riyadh Crescent, Pachuca and Salzburg Red Bull.

Mastantono is 17 years old and will turn 18 on August 14 this year.