The 36 clubs in the 2026/27 UEFA Champions League league phase have submitted their squads, but a registered squad is not simply a list of every senior player under contract. UEFA separates eligible players into List A and List B, applies locally trained-player rules and allows another set of changes before the knockout phase.
Those rules explain why a new signing can occasionally be left out, why academy players may appear without taking a senior squad place, and why a club cannot always replace an injured player immediately.
What is Champions League List A?
List A is the club's main European squad. It can contain up to 25 players, but eight places are reserved for locally trained players. At least four of those reserved places must be filled by players trained by the club itself.
UEFA divides the locally trained group into two broad types:
- Club-trained players: players registered with their current club for three complete seasons, or 36 months, between the ages of 15 and 21.
- Association-trained players: players developed for the required period by another club in the same national association.
The rule does not force a club to name eight locally trained players. Instead, a shortage reduces the maximum size of List A. If a club has only seven eligible locally trained players, for example, it cannot simply fill the missing reserved place with another overseas-trained senior player.
Why some clubs register fewer than 25 players
The 25-player figure is a maximum, not an automatic entitlement. A club that cannot satisfy the locally trained requirements may have to submit a smaller list.
This is why transfer activity and academy development affect European squad planning in different ways. A club may have enough players for its domestic league but still face a tighter selection for UEFA competition because national competitions can use different registration rules.
Goalkeepers are part of the same planning problem. Clubs need sufficient cover across the league phase, but all senior options must fit within the applicable list and quota structure.
What is List B?
List B is designed for younger players who have spent a meaningful period at the club. Eligible players can be added during the competition without occupying one of the 25 List A places.
That flexibility is valuable for academy graduates. A young player can move between youth and senior football, provide injury cover and earn Champions League minutes without forcing the club to remove an established List A player.
Age alone does not guarantee eligibility. The player must also meet UEFA's continuous-registration requirements. A recently signed teenager may therefore be too young for a normal senior profile but still ineligible for List B because he has not been at the club long enough.
Can clubs change their squads during the league phase?
The main List A deadline arrives before the league phase. Clubs cannot freely rewrite that list before every match. Limited provisions may apply in specific circumstances, including long-term goalkeeper unavailability, but ordinary form, tactical preference or a short injury does not create an unlimited replacement right.
List B is more flexible. Eligible players can generally be registered shortly before a match, allowing clubs to respond to development and availability across the season.
Fans should check the latest official club squad page before assuming an unlisted player is injured. The reason may simply be registration, homegrown balance or a coaching decision.
What changes before the knockout phase?
After the winter transfer window, clubs that advance can register a limited number of new eligible players for the knockout phase. That creates room for January signings and for players whose circumstances changed after the original league-phase deadline.
The additional registrations still have to fit the wider squad rules. A club cannot use the winter update to abandon locally trained requirements or expand List A without limit.
The modern rule is also less restrictive than older versions of European competition. A player who represented one club earlier in the season may, subject to the current regulations and registration limits, be eligible for another club in the knockout rounds.
Why the rules matter on matchday
Registration is separate from the match squad. Being on List A or List B makes a player eligible for the competition; it does not guarantee selection in the starting eleven or among the substitutes.
Managers must balance several layers:
- Is the player registered and eligible?
- Is the player fit and available?
- Does the player make the matchday squad?
- Does the tactical plan require him to start?
That distinction is especially important when lineup graphics circulate online. A player missing from one match squad has not necessarily been removed from the Champions League list.
The bottom line
Champions League List A is capped at 25 and reserves eight places for locally trained players, including four club-trained places. List B gives qualifying academy-age players a separate route into the competition. Clubs receive another limited registration window before the knockouts, but they cannot change their senior squad freely throughout the league phase.
For fixtures and competition context, see our Champions League league-phase format guide or browse the latest Football coverage.
