I have two kids with two different personalities. They both played college baseball/softball.
When my son was eleven we had just switched leagues. All eyes were on him. He was expected to be a diffference maker in all stars. One game he made three errors. On he way to the car he commented he stunk today. I asked him if he wanted to get in some practice tomorrow. He responded, “I’m good. I just stunk today. I’ll be fine.” He knew he was supposed to be the best.
My daughter was not only a physical late bloomer. She was a talent late bloomer. I don’t think I ever heard anyone say so often, “I have to be better tomorrow.”
I never once had to drag these kids to a field/court for practice in any sport. It was built into them to become the best they could be. Maybe it came from the work ethic, effort and attitude they saw from parents. They never had to be taught confidence. They constantly drove themselves to be better. Confidence comes from being prepared.