If he is doing it as a hobby, why not throw the guy a bone. He isn't making any money doing this, he's just doing it because of he loves the sport and the kids ( I assume - not knowing the chap ). Why not work with him, privide him will little ones and like you said, if your in this for the money - refer them to your site. Sometimes I think some forget they started doing this just becsuse they love the kids and want to capture it... it wasn't the beginning of some photo empire. The Coaches are donating their time, parents help out in many ways to make this a great experience for the kids... what in the heck is a picture here or there... particularly when there is no money being made anyway. I just don't get it sometimes.
Now if you do this to make your mortgage, and the local paper wants them.... that's another story all together.