At 23:59 CET on Wednesday 2 September 2026 the window that really matters for clubs in Europe closed: the one for squad lists. This is not paperwork to be tucked away at the bottom of the page. It is the rule that decides who can take the field across the eight league-phase matches, and this year it produced a result worth looking at closely: two of the four Italian clubs filed twenty-three names instead of twenty-five, and not because they had run out of players.
The rule, as written
UEFA’s text is precise and needs reading in full, because every line creates a different constraint.
| Item | Rule |
|---|---|
| List A deadline | Submitted by the club and validated by the association by 23:59 CET on 2 September 2026 |
| List A capacity | Maximum 25 players |
| Goalkeepers | At least two of the twenty-five |
| Locally trained | Eight of the twenty-five places reserved exclusively |
| Association-trained | No more than four among those eight |
| List B | Unlimited, born on or after 1 January 2005, with residency requirements |
| List B filing | By 23:59 CET on the day before the match |
| Knockout additions | Up to three, by 23:59 CET on 4 February 2027 |
| Injury replacement | Outfield player out at least 60 days, goalkeeper at least 30 |
The distinction between the two categories of locally trained players is the one most often missed. A club-trained player came through that club; an association-trained player came through another club in the same country. Eight locally trained players are required, but at most four may be of the second kind. A club with ten domestic players in its squad can therefore still fall short, if it bought all of them from other clubs instead of developing them.
The point that changes everything: the places are lost, not replaced
Here sits the part that makes this a tactical rule rather than an accounting one. If a club cannot fill the eight reserved places, it may not put any other player in them: the list gets shorter. One missing locally trained player equals one place fewer, and the team goes into Europe with fewer available players than its opponents.
That is why a 23-man list is almost never a footballing choice. It is the number left over once the arithmetic of the regulation has done its work.
Inter and Napoli, the same number
The two Italian lists filed before the deadline tell the same story with different names.
Inter lodged twenty-three players on List A: three goalkeepers, Josep Martinez, Raffaele Di Gennaro and Ivan Provedel; nine defenders, among them John Stones, Manuel Akanji, Benjamin Pavard, Alessandro Bastoni, Federico Dimarco, Yann-Aurel Bisseck, Carlos Augusto, Djed Spence and the young Mattia Marello; eight midfielders, from Nicolò Barella and Hakan Calhanoglu to Piotr Zielinski, Petar Sucic, Andy Diouf, Curtis Jones, Henrikh Mkhitaryan and Luis Henrique; three forwards, Lautaro Martínez, Marcus Thuram and Ange-Yoan Bonny. On List B the club named Aleksandar Stankovic and Francesco Pio Esposito.
Napoli, coached by Massimiliano Allegri, also filed twenty-three names. Left out were Alessandro Buongiorno, injured, along with Luca Marianucci and Giovane. Inside are the two players back from loan spells, Noa Lang and Lorenzo Lucca, and the summer signings Costantino Favasuli and Benoit Badiashile.
In both lists the players meeting the locally trained requirement number seven, one short of the eight allowed for: hence twenty-three instead of twenty-five. One honest qualification: the club statements publish names, not each player’s classification as club-trained or association-trained. The count of seven circulates through journalistic readings of the lists, and the internal composition of that group cannot be verified against a public document. The final number, though, can be: twenty-three names, counted one by one.
What it costs on the pitch
Two fewer places is not an administrative detail. The league phase runs to eight matches between September and January, played inside a calendar that also contains a domestic league and a cup. Two players fewer means fewer rotations, fewer answers to a red card or a run of injuries, and a shorter European bench than an opponent who filled those places.
The regulation leaves two valves. The first is List B, which is unlimited and can be topped up until the day before each match: but it may only contain players born on or after 1 January 2005 who have been at the club for a continuous period, so it is not a reserve you can go out and buy. The second is injury replacement: an outfield player out for at least sixty days can be temporarily replaced up to matchday six, and for a goalkeeper thirty days is enough. These are valves, not remedies: a locally trained player missing in September is still missing in January.
Then there is the window of 4 February 2027, by which clubs that qualify for the knockout phase may register up to three new players. That is where the winter market meets the list, and where the clubs that filed twenty-three names today can catch up, assuming they buy the right profile.
The calendar nobody looks at: in Scotland the window shut later
One last effect of the 2 September deadline is worth isolating, because it overturns the common idea that the market ends at the same moment for everyone.
The Scottish window closed at 17:00 on Thursday 3 September 2026, that is a little over eighteen hours after the UEFA list deadline. For a Scottish club playing in Europe, then, the real deadline was not its own league’s: it was UEFA’s, the day before. A player bought on the afternoon of the 3rd would have been properly registered in Scotland and properly unusable in Europe until February.
Celtic reacted in the only way available: by compressing their market. In little more than twenty-four hours, before Wednesday evening’s deadline, they closed six deals, among them Dutch midfielder Joel van den Berg from PSV and Swiss full-back Jordan Lotomba from Feyenoord, plus four loans, goalkeeper Sam Johnstone from Wolverhampton, midfielder Oliver Sorensen from Parma and the two 18-year-old Chelsea players Shim Mheuka and Landon Emenalo. Six signings in a day is not frenzy: it is a calendar read correctly.
The lesson in method
Squad lists look like the boring part of the job and are instead the place where regulation turns into development. A club that has not produced enough of its own players over the past eight years does not find out in June, when it buys: it finds out at 23:59 on 2 September, when it finds it can register twenty-three instead of twenty-five. No August signing can correct that line, because that line measures something built over years rather than inside a transfer window.
Sources: uefa.com, official page on squad registration for the 2026/27 Champions League league phase, for deadlines, capacity, locally trained quotas, List B requirements, the 4 February 2027 window and injury replacements; official lists published by Inter and SSC Napoli and their coverage in the specialist press for names and for the locally trained count; STV News and the Scottish press for the closing time of the Scottish window and for Celtic’s deals. The classification of each player as club-trained or association-trained is not published by the clubs.
Frequently asked questions
When was the deadline for the 2026-27 Champions League league phase squad lists?
List A had to be submitted by the club to UEFA and then verified and validated by the national association by 23:59 CET on Wednesday 2 September 2026. UEFA states this on its own site. List B has no single deadline: it can be updated during the season, provided it is filed by 23:59 CET on the day before the match in question.
What exactly does the locally trained rule say?
List A may contain a maximum of 25 players, at least two of them goalkeepers. Eight of those twenty-five places are reserved exclusively for locally trained players, and no more than four of those eight may be association-trained rather than club-trained. A club-trained player came through that club; an association-trained player came through a different club in the same country.
What happens to a club that does not have eight locally trained players?
It does not replace them with other players: it loses the places. The list is reduced accordingly, one place for every missing locally trained player. That is why a team can lodge a 23-man list while having a larger squad and no injuries to leave out.
How many players did Inter and Napoli register?
Twenty-three each. Inter's List A contains seven locally trained players and Napoli's likewise seven, according to readings of the lists published by the two clubs. The breakdown between club-trained and association-trained does not appear in the club statements, so the exact composition of that group cannot be verified against a public document.
Who can be on List B?
Players born on or after 1 January 2005 who, since their fifteenth birthday, have been eligible to play for the club for two uninterrupted years or for three consecutive years with a maximum one-year loan spell. The number is unlimited and the list can be topped up during the season. Inter named Aleksandar Stankovic and Francesco Pio Esposito on List B.
Can the lists be changed after 2 September?
Only in specific cases. An outfield player injured for at least 60 days may be temporarily replaced during the league phase up to matchday six, and a goalkeeper may be replaced for an injury lasting at least 30 days. Clubs that advance may then register up to three new players by 23:59 CET on 4 February 2027.
