Sometimes the decision is made for them.....
My son loves pitching and has known for awhile that he belonged on the mound but he loves the game and wants to play. On his summer team, he is given that opportunity and contributes both offensively and defensively. In HS, from his sophomore year on, he was never even given the option. As a junior last year, during practice, he tried to work out at first when he was done with his pitcher's drills until the coach told him that he was never going to play there so he might as well sit down. He sat down and did not ask to practice there again. He was not allowed to hit even in the batting cages.
He has a new coach this year who isn't quite so harsh but the mold was set and he still does not get to play the field or bat although he is allowed to take batting practice.
He, too, will be playing college ball next year as a pitcher. He knows that he will not do anything beyond that for the team. He had always hoped he could do more in HS since he knew his days of playing in every game and hitting would come to end. In fact, he mentioned that he wants to play this summer just so he can play a fielding position and hit in the line-up one more time.
If you asked him, he would tell you to keep playing wherever you can until you are asked to give it up.