so I guess I can see how she might have like, sprained her wrist blocking a ball.. maybe. (but not from the angle the manga shows it hitting)... but why would she need to 'rest'? How is sitting in the infirmary any more restful than sitting in class?
Like I've injured myself in sports, lots of sprains and the like, but if I ever had to 'rest' it was to do something like, icing an injury. Oh well, I guess it's just supposed to be plot or something.