First things first, your son DOES have the power to control himself, he is choosing not to.
I think it's a good idea to go back to counseling. I'm a baseball "nut" myself and I've coached a lot of kids over the years. There have been a few kids who have "talked back" to me and my guess is that, for some reason, they have been allowed to do this at home and that breaks my heart. Kids today seem to think that they are equal to adults. They seem to think their opinion is as valuable as an adult's opinon. In other words, they think they are equal to an adult. This is wrong. Kids are kids. He has had 11 years of experience in life. Yout have had many more. To allow him to act in a disrespectful manner to his coaches (and the other adults in his life) is not going to help him in the future.
Your son needs to learn to respect authority because everyone has to anser to someone. Someday he will have a boss. He will HAVE TO respect the authority his boss has over him or he will be fired. He will have many, many teachers over the years. He will need to respect their authority or he will not graduate. So when he disobeys or disrespects you, he needs a consequence. I don't mean spank him. I mean you need to establsih the fact that you are the adult and you are IN CHARGE. He needs to understand that he is a child and he is not in control of the world. To allow him to think that his opinion matters as much as that of an adult (by allowing him to "talk back" to you) is wrong. It creates a world in which there are little, if any, boundaries for your son. Kids want and need boundaries. Your son is acting out so that someone will show him the boundaries.
Let me warn you, this will not be easy. Your son is used to getting his way so prepare yourself for the "battle" that is in your future. You owe it to your son to help him learn to accept legitimate authority such as parent, teachers, coaches, etc. When you start to give consequences for back talk, his behavior will GET WORSE for a few days of weeks. Expect that and don't give in.
The carazy thing is that this situation is brought about out of love. You have loved your son so much you have allowed him to act this way. You didn't realize that acting this way was going to lead to trouble. That's okay. WHat's done is done. Decide right now that you will not tolerate disrespect and that you owe it to him to reestablish your role as parent to your son. Trust me when I say, he's been waiting for this time.
Thanks for writing into the board. Let me know if you have other issues/questions.