well brother, numerous things could cause his feet to swell(and we cant diagnose him on a forum). i doubt that the shot has anything to do with the feet. A shot in the glute would not be related to his feet swelling, so i wouldnt look at that and try to find why it is reacting. I also assume the injection site is fine or you would have mentioned that too, or should have anyway. one thing that comes to mind is that pregnant womens feet swell when hormones adjust during pregnancy. I would think that his estrogen would be the culprit in that case, but i would also think that he would know this and be taking some anti-e's if he were a veteran. also, for estrogen to be the cause he should have had many symptoms prior to this, due to the fact that the estrogen would more than likely be EXTREMELY high(so i doubt this also had anything to do with it). I would get his kidneys checked. if he is having a problem with his kidneys, he may not be flushing water out of his system properly. Also, diabetics have many problems with circulation in the legs and feet, so maybe its related to insulin release in his body(does he use insulin with his cycles?) Bottom line: get his ass to a hospital and forget about the stupid softball game(thats immature to even consider that as part of the overall equation at this point if these symptoms are severe).
one more thing, if the swelling isnt going down, i would actually be careful wih the amount of fluids consumed until he sees a doctor. it may help flush his system, but if not it may cause the problem to worsen. just my .02 | 
