According to Mundo Deportivo, a major variable in Real Madrid's squad next season is the future of Mastantuono. The Argentine youngster joined Real Madrid as a blockbuster signing but must wait until he turns 18 to make his official debut. The club previously used his age to register him in the Castilla squad, thus freeing up a spot in the 25-man first-team roster.
The report states that if Mastantuono remains with Real Madrid next season and is not loaned out, the club will not be able to continue with this registration plan. According to current La Liga rules, La Liga will not allow him to continue to be registered as a youth team player.
La Liga rules clearly state: As long as a player plays for the first team for 30% or more of the team's total game time in a single season, he cannot continue to belong to the club's youth team. Mastantuono's attendance data exceeds this threshold.
This season, he played in 23 out of 38 La Liga matches, accumulating 1037 minutes of playing time. In the Champions League, Mastantuono played in 8 matches, accumulating 293 minutes of playing time out of the team's total 1080 minutes in the Champions League.