hi, before returning to football field, balance on one leg, proprioception of the affected leg must be enhanced, by using wobble board, single leg stance, lunges, carico run, sideway runn, brisk walk n jog, etc. dont forget to strengthen the intrinsic muscles of the foot. follow by pylometric activities such as jumping and landing, fast jog/run, other rapid/quick response activities which always involved in football game..
dont forget to strengthen the ankle muscles s well.
hope all these are useful..