It depends on your son's age and what you mean by "overlooked."
 
You didn't mention your son's age but either he is of an age where everyone gets to play regardless of ability or he is of an age where those with ability generally get to play more.  How old is he?
 
Also do you mean the other kids are overlooking him (like not passing the ball as much as they should) or is he being overlooked by the coaches and not being played as much?
 
There is of course the possibility that he is not as good as he thinks he is and it is time for a reality check.