I heard that the prize for winning one is massive too, although I'm not sure if that money will go to the players instead of the club. That being said, it is possible that the player and the club draft a contract with add-ons, offering extra bonuses when they appear in the Club World Cup, score goals, or assist, and so on. I also don't get why it is shameful to take a lower salary. It is not like he's begging someone if he accepts that deal anyway. In the end, it's just business and a desire to play football.