I'm a athlete. always have pain in my left hip. the pain is on the outermost part of my hip and by the groin area at times. hip isn't that flexible.

Multiple causes: Your pain could be due to overuse injuries to your adductor (groin) muscles, and your it band (outside part of hip/side of leg) your groin pain could also be due to an injury to the bumper inside your hip called the labrum. I would recommend an evaluation by a sports medicine (either primary care or orthopedic) specialist if this is a longstanding problem.