I searched about the home-grown rule in Prem and UEFA and it calculates the season and loan deal differently.
Prem allows players to be registered as U-21 player even when the player is out on loan (even in foreign clubs) while UEFA doesn't.
Also for prem, the season in this case is from end of summer transfer window to last home match while for UEFA one it starts from first game of league. Also UEFA considers England and Wales differently, while PL doesn't.
UEFA also technically doesn't use the term HGC and HGN. They officially use Club-Trained Player/Association-Trained Player
But UEFA just applies rules by the Premier League. It makes people confusing and also means FM is not implementing the rule properly.
FM should apply this differently.
Here are some examples
1. William Saliba (Arsenal) - He was registered as a U-21 player for Arsenal in Premier League but he has spent his loan spell in France. So he's a homegrown in Prem while he's not in UEFA (since he spent only half a season as an Arsenal player and then got loaned out to a foreign country)
2. Joe Rodon and Ben Davies - The FA regards England and Wales as the same so both are HGN in Premier League, while UEFA considers them different so they are not HGN for English clubs in European Competition.
3. Matt Doherty - He spent 2.5 season at Wolves U-21 and then had half a season at Scotland but this doesn't matter for PL homegrown. But it does matter for UEFA homegrown. Also he signed for Wolves after the season has started so his first season at Wolves is not considered a full season by UEFA.
4. Pape Sarr who has signed for Tottenham Hotspur will have the same issue with Saliba since he had a loan spell in a foreign club.
5. Lukaku is considered HGN for Chelsea since he had a loan spell at domestic clubs but not considered HGC by UEFA (same with current FM homegrown rule)
Related Regulations by FA
<Section A 1 235>
“Home Grown Player” means a Player who, irrespective of his nationality or age, has been registered with any Club (or club) affiliated to The Football Association or the Football Association of Wales for a period, continuous or not, of three Seasons or 36 months prior to his 21st birthday (or the end of the Season during which he turns 21) and, for the purposes of this definition of “Home Grown Player”, a Season will be deemed to commence on the date on which the relevant Summer Transfer Window closes and expire on the date of the final League Match of the Season;
<Section V 44 reference>
The cap on U21 Non-Home-Grown Players set out in Rule V.44 is applicable per Season (which, for the avoidance of doubt, includes the Summer Transfer Window immediately prior to the Season). A Club shall be entitled to register U21 Non-Home-Grown Players without obtaining a governing body endorsement where such Players will be loaned out to clubs outside of the United Kingdom without first participating in League Matches. If at a later date that Club wishes such Players to participate in League Matches it must apply for a governing body endorsement in respect of the Player, who will then (if he is an Under 21 Player) be counted towards the cap on U21 Non-Home-Grown Players set out in Rule V.44 (and any subsequent cap on the number of new U21 Non-Home-Grown Players that the Club may register).
Related Regulations by UEFA
An "association-trained player" is a player who, between the age of 15 (or the start of the season during which the player turns 15) and 21 (or the end of the season during which the player turns 21), and irrespective of his nationality and age, has been registered with a club or with other clubs affiliated to the same association as that of his current club for a period, continuous or not, of three entire seasons (i.e. a period starting with the first official match of the relevant national championship and ending with the last official match of that relevant national championship) or of 36 months. In the context of this paragraph, the season immediately preceding a player’s 15th birthday may be counted if his birthday is after the last match of the relevant national championship but before or on 30 June (winter championships) or 31 December (summer championships), and the season immediately following his 21st birthday may be counted if his birthday is on or after 1 July (winter championships) or 1 January (summer championships) but before the first match of the relevant national championship.
(Club-Trained Player has basically the same sentence but for club)
