Would it be possible to change players nationality after playing for a certain team over 5 seasons? It could be done for players that are bought before 18 years old and had been trained in different country, so they can keep their name but also to get second nationality.

That could be useful in case that there is no national team or the origin country do not need that player, he can play for the national team.

Example 1. You bought 17 year old player from Greece that doesn't have national team. Player is trained in Germany and in age of 23 he can play for German national team.

Example 2. You bought 17 year old player from Germany. Player is trained in Italy and he can play for German national team. In case that Germany did not invite the player in national team before age of 23, after that he can play for Italy as his second nationality.