"If I'm putting all the effort into my training, working my butt off to get two competition points and the bloke standing next to me isn't of the same mindset, as a player I'd have some question marks.
"As a coach, I haven't thought about it too much, but there's no coach in the world that would have someone like that in their team."
While Simona's suspension does leave the door open to him one day return, Greenberg said the governing body was unlikely to register him as a player.
Doubt surrounds Simona's playing future, with England's Rugby Football League indicating the door would be closed on him playing in the Super League.
Flanagan said there was no excuse for betting on games and players were acutely aware of the strict anti-gambling policies.
"You have to comply with some things when you sign that NRL contract, you're not Joe Public anymore," Flanagan said.
"Our players are really well educated on that, every club is, there's no excuse for gambling, they get lectured every year."
