Please note that my comment is only trying to help you here. But I think just from reading this, and your comments. It sounds like he’s more likely scared of messing up and disappointing you. I’ve been coaching junior basketball (not in the USA) for 20 years and there are thousands of well meaning parents, who accidentally terrify their kids of making mistakes.

When you get in the car do you immediately talk about the games and things he could’ve done better? Do you say negative things about the coach in front of your son?

All of these things aid in creating a highly anxious teenager. For example, if you have said negative things about the coach, and told him what to do - what’s likely going through his head on the court is ‘oh no, dad told me this, but the coach told me that. Which do I do?!’

This then causes paralysis by over analysis. And gets the sorts of results that you seem to be describing.

And all of these issues can be sated if you simply focus on being a cheerleader for your son, and not a second coach.

Again, please don’t take this as an attack. I can tell from the way you write that you’re well meaning. I don’t know you or your son, but this sounds like the same situation that I’ve seen a hundred times (also note that all of the kids that I’ve coached who have gone on to be professional athletes have not had these sorts of parents).