It's not for playing poker, is it?
Footballers betting on their own teams is dodgy as fuck. No matter how 'innocent' it may seem, they could be seen as a way to influence the result.
I get that addiction is a problem, but it has to be a pretty serious and impacting one for a player to bet on their own team, playing in the game or not, knowing that it's quite an explicit rule that you are not allowed to do that. I'd have a bit more leniency for players just doing a random acca that will have no bearing on their their team. But Toney and Tonali (and Fagioli?) all betted on their own team's results at one point or other. And that a) shouldn't be allowed and b) that's what they should get help towards avoiding.