And also, I understand why they are not there but wondered if the appearances sheet (or somewhere alternative) could show when a player has not been included in a squad? This data appears to be available too.
Link attached for a player that has FA Cup matches and examples of not being included in a squad.
As far as I can tell, "Not in Squad" appearances can be inferred from appearances and games (i.e, there was a game an the player did not have an appearance for it).
Requested in Kaggle.