A regulatory change that demands extreme caution

Real Madrid head into their Copa del Rey clash against Talavera facing a largely unseen but potentially costly threat. It has nothing to do with injuries or suspensions, but rather with a key modification to the RFEF Competition Regulations that directly affects how reserve-team players can be used during official matches.

Starting this 2025–26 season, the rules no longer impose a minimum number of first-team players on the pitch. Instead, they set a maximum number of players who are not registered with the club’s primary squad. A subtle but decisive change that forces coaching staffs to be far more precise in their squad management.

From minimum to maximum: the new RFEF rule

Until last season, teams were required to keep at least seven first-team players on the field at all times. Any situation — whether through red cards, injuries, or substitutions — that dropped that number below seven could be ruled as an illegal lineup.

The updated regulation flips that logic entirely. Teams are now prohibited from fielding more than four players who are not part of the squad registered for that division, both at kickoff and throughout the match. Even if a first-team player is sent off, there is no infringement as long as that four-player limit is not exceeded.

Franco Mastantuono, a registration that changes everything

This is where the situation becomes delicate for Real Madrid. Franco Mastantuono, despite training and competing with the senior squad, is officially registered with Castilla. As a result, if the Argentine midfielder is on the pitch against Talavera, only three additional Castilla players can feature alongside him at any given time.

Any miscalculation in substitutions, an unexpected red card, or an overlap of academy players could quickly place Real Madrid at risk of committing an illegal lineup, with immediate sporting consequences.

A precedent no one wants to repeat

The concern is amplified by a painful memory in the club’s recent history. In 2015, Real Madrid were eliminated from the Copa del Rey after Denis Cheryshev was fielded while serving a suspension against Cádiz. That incident remains a constant reminder of how costly administrative errors can be.

The Copa del Rey is traditionally the perfect stage to give academy players valuable minutes, but this time Xabi Alonso must manage every decision with surgical precision. Mastantuono represents talent and the future — but also a regulatory variable that leaves no room for mistakes off the pitch.