If they are at Son Heung-min's level, selection isn't even a question of skill

Unless the player themselves refuses to play,
even if they continue to fail to score goals like they are now,
the moment they aren't selected for the national team,
the manager will face immense pressure from people arguing that "their name value alone puts pressure on the opposing team."
And if the results don't follow... just thinking about it is terrifying.
Look at Ronaldo this time; even though he was a dead weight, the manager couldn't bench him.
Unless the player announces their retirement, they will absolutely be selected.