Don't know, if you are to fake an injury, Antwerp game is the ideal moment. Kind of happens to be sick just before a meaningless match. Move on from this anyay.
Remember that at some point, Xavi wanted to sell FDJ and to replace him with Bernardo Silva in the first team.
So i won't be surprised if Frenkie isn't fully committed to this team, as it seems there is actually a lack of trust between some players and Xavi, when it comes to his choices and management of the team.