IF your kid was also flipping the diverter back and forth, he may have worn one of the seals, so yes, they could be related. Other than that, the parts are unrelated. If this is what I think it is, done 3-years ago, it would never have passed code. This assumes (but may not be correct) that the other two knobs are for hot and cold. It would be a rare installation of this type that was actually fed through a federally mandated anti-scald valve. This requirement has been in effect for many years now. They may still sell them, but that doesn't actually mean they are legal to install! Regardless, you may need to take the stem of the diverter out, and get a replacement. If you post a picture of the whole thing, then another with it removed, someone may be able to help you with the part you need.