Hi,
The subgluteal and groin pain may indicate SI joint problem, if the problem lies in SI joint structures good therapist should see if the reason is loocked or opened position of SI joint, for that an X-ray of pelvis on one leg standing could be helpful to exclude pelvic instability, anyway when acute phase passes you should try to strenghten your body CORE muscles before starting any sport activity. Any bacterial desease before the first pain? Good luck