From a relative of mine who is a sports psychologist to whom I forwarded the question:
- Hum....he might keep track of the number of incidents. When it happens, identifying it to the child. That tends to help children understand the specific behaviors that are to be reduced/eliminated. Following in the cognitive/behavioral mode, he might set a goal for the next practice (reduce incidents of the behavior from baseline to x) . Postively reinforcing reduction in the behavior - goal attainment.
He might also look at the environment and see what/who might be reinforcing (sustaining and/or increasing) the behavior (eg., other boys on the team, other parents, TV athletes).
Just some thoughts...