G.B.
I would go above his head and complain. He is not able to be objective in this area. He wants his child to be the star of the team. He has waited since he got married and found out his wife was having a boy for this moment. He is not going to be able to be objective.
He wants his son to get scholarships and to be seen as a fantastic athlete. So I would ask that someone with authority watch the practices and games to see if they are truly on the team but not "on" the team. This is unfair to them, they deserve to be seen and watched for potential scholarships and accolades too.