Why Mendy is out of Real Madrid's Champions League squad: UEFA rule blocks Sergio Martínez from List B

Ferland Mendy will not feature in Real Madrid's Champions League squad. The left-back's absence is the result of two overlapping factors: the sporting need to register Sergio Martínez for a tie in which Eduardo Camavinga, Arda Güler and Bernardo Silva are suspended for the first leg, and a regulatory obstacle that prevents the former Racing player from taking a spot in List B. The club had to free up one place, and the French defender was the one left out.

• UEFA allows only 25 players in List A, but Real Madrid have 26 first-team players plus Sergio Martínez.
• Sergio Martínez does not meet the age and club tenure requirements to be registered in List B.
• Camavinga, Arda Güler and Bernardo Silva are suspended for the first leg of the knockout tie.
• Thiago Pitarch was eligible for List B, but that route does not work for the former Racing midfielder.
• Mourinho already has Cucurella and Carreras at left-back, making it easier to leave Mendy out.

Why Real Madrid cannot register Sergio Martínez in List B

UEFA's rules for List B are very specific. To be eligible, a player must have been born on or after 1 January 2005 and, since turning 15, must have been eligible to play for the club for an uninterrupted period of two years. The alternative is a total of three consecutive years with a maximum one-year loan to a club in the same federation.

Sergio Martínez, who has just arrived from Racing, does not meet either condition. He has not been part of the Madrid academy for the required period, and his age does not offer him a way around the rule. That left only one option to have him available for the tie: putting him in List A, which meant dropping another first-team player.

The 25-player limit shaping Real Madrid's Champions League squad

List A in the Champions League is capped at 25 players. Real Madrid currently have 26 squad members with first-team contracts. Adding Sergio Martínez would take the total to 27, two over the allowed number. One of those extra spots was resolved without drama through Thiago Pitarch, who meets the criteria for List B.

With the young midfielder already placed in that second list, Madrid still needed to open up a space in List A for Sergio Martínez. That is where Ferland Mendy came into the picture. Although his injury was not expected to keep him out for long, he was the most logical candidate given the depth available in his position.

Left-back depth makes Mendy the player to miss out

The technical side of the decision also carried weight. Mourinho has Marc Cucurella and Álvaro Carreras to cover the left side of defence, two options that provide enough security in that part of the pitch. Given that, keeping Mendy in List A was less of a priority than adding another midfielder for a tie in which the middle of the park is already stretched.

The suspensions of Camavinga, Arda Güler and Bernardo Silva for the first leg leave the team short of alternatives in midfield. Losing Mendy for a few weeks looks like a manageable cost if it means gaining depth in an area that arrives at the European tie severely depleted.

The eight academy players included in Real Madrid's List B

While Sergio Martínez cannot be placed in List B, Real Madrid have included eight academy players in that category. In defence, the list features Fortea, Joan Martínez and Mario Rivas. For midfield, Thiago Pitarch, Cestero, Lacosta and Valero are registered. Up front, Yáñez takes the final spot.

All of them meet the age and club tenure criteria set by UEFA, unlike the former Racing player. The split between List A and List B is far from a formality: it determines who can be fielded in each knockout round and forces clubs to plan their squads with precision to avoid being left without key pieces at decisive moments.

What is at stake for Real Madrid in this Champions League tie

The Champions League tie comes at a demanding moment for Real Madrid. Mourinho must manage a squad missing three players through suspension for the first leg and will have to carefully handle minutes for those carrying physical issues. The margin for error is zero, and every squad decision could prove decisive.

The goal is clear: keep advancing in Europe's top club competition. To achieve that, the coaching staff has chosen to reinforce midfield at the expense of a left-back who, despite his status, would not be available immediately due to injury. The bet on Sergio Martínez is driven by an immediate need rather than a rotation whim.

Frequently asked questions about Real Madrid's Champions League squad