Hamstring injury for my kid

Hey everyone! My son is a football player. Last month while chasing the ball, he had an intense pain at the back of the thigh and was unable to walk without limbing. He told that it was not the first time he is suffering from the same pain. So I took him to our family doctor he told that it will good if we take MRI or an ultrasound to diagnose the same. As per his word we carried out MRI and found that he is suffering from hamstring injury, that he got a scar over there. He was asked to take rest for few days. All three days we include the treatment of RICE(rest, ice, compression, and elevation). But there was a swelling over his thigh. So that doctor asked to take advil which can help him. His trainer told about a sports injury chiropractor from a clinic in Toronto. I am planning to take him. Will that be useful? How long should he take rest? What do you think about this treatment? It will be great if you can share your thoughts!