Ange Postecoglou's January transfer calls will involve Yang Min-Hyeok, Timo Werner and Djed Spence

Ange Postecoglou will want further additions for his Tottenham side in the January transfer window but it's worth looking at what must happen to his squad to fit them in.

Spurs have long had issues with keeping within their homegrown and foreign player requirements when it comes to their Premier League and European squads, with the latter often causing the most problems. This season, Postecoglou has had to leave Djed Spence and Sergio Reguilon out of his Europa League squad for that exact reason.

Here's what Tottenham's Premier League and Europa League squads look like right now in terms of keeping within the guidelines and what it means for the January window. For the purposes of this exercise we're not using players who are out on loan elsewhere as they are a problem to be dealt with next summer in these lists.

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Premier League

Spurs haven't got any problems with their Premier League squad, because the rules in this competition are pretty straight forward.

You cannot register more than 17 non-homegrown (foreign) players and the remainder of the squad, up to that total of 25, must be homegrown. However, there is also the bonus in the Premier League that clubs can name any players aged 21 and under within a separate Under-21 list, which frees up space in the main 25-man squad.

For the 2024/25 campaign, Under-21 players have to be born on or after January 1, 2003 to make the list so that means Archie Gray, Wilson Odobert and Lucas Bergvall did not need to be registered on the main list and the same will go for Yang Min-hyeok in January and all will remain on there

When it comes to homegrown players, the Premier League describes one as "a player who, irrespective of nationality or age, has been registered with any club affiliated to the Football Association or the Football Association of Wales for a period, continuous or not, of three entire seasons, or 36 months, before his 21st birthday (or the end of the season during which he turns 21)".

Spurs only have 14 non-homegrown players and the required eight homegrown ones, so can add three more players in the January window with Sergio Reguilon also likely to leave if he can find an exit route this time, which would make it four open spots for players aged over 21.

Premier League non-homegrown players (14 currently, 17 maximum allowed): Guglielmo Vicario, Pedro Porro, Radu Dragusin, Destiny Udogie, Cristian Romero, Micky van de Ven, Sergio Reguilon, Rodrigo Bentancur, Yves Bissouma, Dejan Kulusevski, Richarlison, Son Heung-min, Timo Werner, Pape Matar Sarr.

Premier League homegrown players (8 currently and eight minimum required): Dominic Solanke, Fraser Forster, Brandon Austin, Alfie Whiteman, Ben Davies, James Maddison, Brennan Johnson, Djed Spence.

Notable Under-21s players: Archie Gray, Lucas Bergvall, Wilson Odobert, Will Lankshear, Mikey Moore, Alfie Dorrington.

Europa League

The Europa League squad is where things get messy because of their overly complicated requirements.

UEFA's rules state that no club can have more than 25 players on their A List during the season, of whom at least two must be goalkeepers.

A big difference from the Premier League rules is that the under-21s list is called the B list and in UEFA's eyes it only applies to players who have spent two years at the club, so that means Odobert, Gray and Bergvall do not apply and neither will Yang when he arrives next month.

The other major difference for the A list comes in the classification of homegrown players, which in European competition falls into two different categories.

The rules say that "as a minimum, eight of those 25 places are reserved exclusively for 'locally trained players' and no club may have more than four 'association-trained players' listed among those eight places. If a club has fewer than eight locally trained players in their squad, then the maximum number of players on List A is reduced accordingly".

So conversely, if you have more than four association-trained players to register, the surplus must be placed in the main A list.

So what is a locally-trained player? There are two types. One is 'club-trained players' who were on the club's books for three entire seasons or 36 months between the ages of 15 and 21. The other is 'association-trained players' who were on another club's books in the same association for three entire seasons or 36 months between the ages of 15 and 21.

When it comes to the B list, a player may be registered on it if he is born on, or after, 1 January 2003 and has been eligible to play for the club for any uninterrupted period of two years since his 15th birthday by the time he is registered with UEFA – or for a total of three consecutive years with a maximum of one loan period to a club from the same association for a period not longer than one year. Players aged 16 may be submitted if they have been registered with the club for the previous two years without interruption.

It's also worth noting that a UEFA rule change a couple of years ago meant that Welsh players who came through at clubs within the English FA can now be counted as homegrown, which means Ben Davies is considered homegrown, albeit 'association-trained'.

So with that all in mind, the below numbers show that Spurs have 17 non-locally trained players, seven associated-trained players and just two club-trained players. The latter means that the club have to leave two spaces in their squad as they are meant to have four so can have an overall squad of just 23 players.

With Djed Spence and Sergio Reguilon currently out of the Europa League squad, there is also no room currently for Yang Min-hyeok or any other potential January signings if Spurs were to make the knockout stages. Postecoglou will have to remove players first if anyone new is to get a chance to play in Europe.

European non-locally trained players (17 currently, 17 maximum): Guglielmo Vicario, Pedro Porro, Radu Dragusin, Destiny Udogie, Cristian Romero, Micky van de Ven, Sergio Reguilon, Rodrigo Bentancur, Yves Bissouma, Wilson Odobert, Dejan Kulusevski, Richarlison, Son Heung-min, Timo Werner, Pape Matar Sarr, Lucas Bergvall, Yang Min-Hyeok.

Association trained players (7 currently, four can be used in exclusive slots): Dominic Solanke, Fraser Forster, Ben Davies, James Maddison, Brennan Johnson, Djed Spence, Archie Gray.

Club trained players (2 currently, four required): Brandon Austin, Alfie Whiteman.