Bulldog is right. It goes both ways. I know a very good HS athlete who was a key player on the football team. Called in "sick" for a football game so he could attend a baseball showcase.
I know enough HS coaches to understand their frustration at times. 20 players, 10+ of their parents think they should play college ball. Coach is just trying to make his HS team competitive and as good as they can be by running a summer program - giving the players a place to play with good coaching. Parents gripe because they read this to mean that they have to attend, but all that is really needed is communication and maybe a little bit of give on both sides.
For us, through 2 very different HS programs and coaches every single speed bump related to college exposure or recruitment (and even a few other things) were easily mitigated by honest and respectful communication. Try it, it might just work.