What Is The Treatment For Radial Head Fracture?

Hi. I think the doctor said my son has an acute fracture of the minor radial head? He was is a plaster cast for two weeks and now they have taken it off so that the joint does not get stiff. We were told however it still takes 6 weeks to heal and he should not be playing soccer or running. If he can not return to normal activities does it make sense of a 9 year old not to have a cast?