No NRL player should get paid for charity work. The purpose of Charity work for well-paid high-profile sports stars is that is it supposed to make them look like the give something back to ordinary people in need rather than appearing to be nothing but accomplices in an otherwise useless bread-and-circuses freak show. "Look at these sick kiddies we have visited. Aren't we all top humans? Please ignore those episodes of alcohol-fuelled domestic violence and our fancy cars."
Taking money for doing that instead of just doing it for free is disgusting. $90,000 is a pretty decent salary! It would employ an extra part-time nurse, for example, or maybe put some high achieving but otherwise poor Aboriginal person through a medical degree. Instead it's used to feather the nest of some already overpaid sports star.
This is all before we even start to consider if the source of the funds (e.g. medicare) makes it even worse than it looks.