Yeah I think a lot misunderstand the squad rules.
You’re allowed to register 25 senior players domestically and for European games.
Domestically 8 of those places can only be taken by senior players who have spent 3 full seasons at a club in the English football league’s system (which includes some Welsh clubs like Swansea and Cardiff for example) and if you have less than 8 such players you can’t list the full 25.
On top of this you can register as many under 21s as you like.
There’s a youth rule that I think applies to both domestic and European squad rules but it may just be Europe. That is if they’ve been at your club for less than 2 full seasons then, if you want to use them, they take a senior slot.
European squad rules also complicate things a little too. As well as having 8 places in the senior list only able to be filled by association trained players like above 4 of those places can only be taken by players trained by your own club. This means a lot of clubs don’t actually max out the full 25 man squads they are allowed in Europe.
Our current squad;
Notable under 21s; Kelleher, Grabara, Jaros, Alexander-Arnold, Williams, Hoever, Van Den Berg, Koumetio, Larouci, Woodburn, Jones, Elliott, Brewster.
Club developed; Gomez, Wilson, Awoniyi.
Home grown; Phillips, Henderson, Milner, Oxlade-Chamberlain.
Foreign developed seniors (maximum of 17 can be registered); Alisson, Adrian, Karius, Van Dijk, Matip, Robertson, Tsimikas, Fabinho, Wijnaldum, Keita, Grujic, Shaqiri, Minamino, Firmino, Mane, Salah, Origi.
At least one of the above now needs to either leave or not be registered and used exclusively with the under 23s with Thiago arriving. I still expect 3 of them to leave. Also a note on Elliott he will take up a senior role due to only being with us for one year so far. Same with Van Den Berg but hes just likely to be left off lists as he’s seemingly now behind Hoever and Koumetio in the pecking order and maybe Phillips too if he stays.
Open to edit out any mistakes I’ve made guys.