If you think you just have to worry about steroids because of guys like Bonds and Sosa then you need to do a little research. If you don't want him to be tempted with steroids, keep him away from all sports and don't let him join a gym.
I played with guys in high school on steroids. That's where guys get tempted. It's not because they idolize Major Leaguers. Young guys get tempted because they see their friends do it. They see the results their friends and teammates get.
And as someone stated, steroids or PEDs are not a magic pill. The guys taking PEDs spend more time in the gym than anyone. It doesn't make you a better hitter either. So many guys take some type of PED, get stronger but still can't hit.