I think that you need to let your son who made the team play, and use it as a learning experience. It is not fair to your son who made the team to hold him back- he may end up resenting his brother.
They are not going to be equal all their life, and it looks like they are finding that out now. Maybe it's time for your other son to experience a new activity? Use it as a learning experience, and stress that no matter what, they need to support each other as family. You have a great opportunity to teach a wonderful lesson that can work out well if you play your cards right
