I had a situation in an indoor match recently ( i didnt post it in the indoor thread as i think it applies to outdoor as well) where we had a player injured with the blood rule and therefore had to go off the field. But we werent allowed to put anyone else on the field to replace him so had to defend the corner with one player short. Obviously this doesnt affect outdoor as much as you have excess players who would be running back from halfway. Why not allow a defensive team to substitute on a PC in case of injury/blood rule??