Ashok, I would suggest you to please get the correct information first. Do you know at what age people in those countries that excelled in sport enroll children? Running is natural but there are strenuous sports like Gymnastics for which stamina build up is done by long distance running. And how many of the older players/ sportsmen/women who have started at 3 years of age have developed problems due to their early entry? Does any one have seen any existing anomaly or indicative future one, due to his long distance running?
The coach have treated the boy as a normal child should have been. Those who have physically seen the boy during training can only say as to whether there was anything wrong.