It's quite a stretch to call the practice of Ramadan "unprofessional" especially if you understand religion. Momo is a muslim, he fasts, and because of his religion he thinks he's going to be 100% and he will give you his all even though it's isn't. The guy is attempting to balance religious belief with professional football. This is where the manager comes in. Fasting will slow Momo down especially when he isn't able to eat before the match, the manager knows this. It's the manager's job to know that during a mid day match against Catania you shouldn't start him and you probably don't need him either.