@irontoenail - A friend of mine recently stubbed her toe while she was training for a marathon, and it turned out to be broken. She was absolutely devastated at first, but then she negotiated with her trainer and the doctor. She realized that she would still be able to train in the swimming pool and in the gym without hurting her toe.
It's not perfect, but she should still be able to compete in the marathon. So, depending on the injury, there might be a way around it.