The debut of Real Madrid in the 2025-26 LaLiga season against Osasuna is generating excitement not only because it marks Xabi Alonso’s official start as manager at the Santiago Bernabéu, but also due to the possible appearance of one of the club’s brightest new prospects: Franco Mastantuono. The young Argentine, signed from River Plate, has already begun training with the first team and has been included in the squad list for the opening match.

What Is Mastantuono’s Registration Status?

Although many expected him to be registered directly with the senior squad, Real Madrid chose to list Mastantuono with Real Madrid Castilla. This means he will wear the No. 30 shirt, since RFEF rules require players registered with the reserve team to use numbers above 25. However, this does not prevent him from playing with the first team. Just as happened with Vinícius Jr. and Rodrygo in their early years, Mastantuono will be able to alternate between Castilla and the senior side throughout the season.

Is He Included for the Osasuna Match?

Yes. Real Madrid named Mastantuono in the official squad for their opener at the Bernabéu. While a starting role seems unlikely, there is a realistic chance the Argentine will make his debut coming off the bench. His inclusion highlights Xabi Alonso’s confidence in him after an impressive preseason and strong training sessions with the squad.

What Expectations Surround His Debut?

At just 18 years old, Mastantuono arrives with the reputation of being one of South America’s most exciting young talents. In his official unveiling, he expressed both excitement and awareness of the challenge that comes with wearing the famous white shirt. For Xabi Alonso, his versatility as an attacking midfielder or central playmaker offers tactical options in a midfield that blends youth with experience.