Nationality of World Cup players

Well, a player can only play for one national team. For example, if you are from China and haven't played for China, you can join the South Korean team to participate in the competition, but once you join the South Korean team to participate in the competition, you can't play for China.

If you have played for China before joining the Korean team, you can only play for China all the time.

In other words, once you represent a national team in the national team competition, you can only represent that national team for life. If not, you can choose any team in your country of nationality.

Ps: A person can join the nationalities of several countries at the same time.