Dear as you are in contact sports there high chances of secroiliac (pelvic joint) problem and becouse of it you may have feeling of imbalance.
You have to visit any PHYSIOTHERAPIST who have knowledge of spinal manipulation he will help you to correct it.
Or meet good Chiropracticner he will help you.
Health Tips
you can check your self also with the help of standing photographs of your in minimal clothes clicking by some one else .
and check your shoulders, nipples,pelvis level.
it should be at same line.
maintain correct posture , do core exe.