- UEFA regulations divide squad registration into two categories: List A (senior players) and List B (U21 players). Each club can only register a maximum of 25 players on List A.
- Within those 25 players, 8 must be “homegrown”, while the remaining 17 slots can be filled by non-homegrown players.
- A “homegrown player” is defined as someone who has trained with the club (or another club in the same national league system) for at least three full seasons between the ages of 15 and 21.
Liverpool currently has only 5 homegrown players, which means they can register just 22 players instead of 25. Out of those 22, Liverpool already has 18 non-homegrown players, but UEFA rules permit a maximum of 17.
Rio Ngumoha cannot be registered on List B because he is only 17 years old and has not yet completed two full seasons at Liverpool. The only option is to include him on List A, which forces the coach to remove another non-homegrown player. In this case, that player is Chiesa.
In short: Since Ngumoha is ineligible for List B, the coach had to sacrifice one List A slot, and Chiesa was the one left out.