Hello, welcome to Healthcaremagic. The injury you suffered is very common in contact sports and should be treated with respect as impact to muscle can cause more damage than you might expect. If the treatment is not correct or is treated too aggressively then myositis ossificans
can occur which seems to be your case. In this condition bone will grow within the muscle (called calcification) which is painful. The bone will grow 2 to 4 weeks after the injury and be mature bone within 3 to 6 months. You must see a sports injury
specialist or orthopedic doctor. You might need to get an X ray
of the muscle. You must give rest to muscle for atleast 3 to 4 weeks. In some cases it might even need surgery. Wish you good health.