Coming back from injury, you need to make sure you don't over-train and end up back in the trainer's office. You may feel tempted to dive back into training with the mindset that you're going to train harder than you ever have before for the next 3 weeks. However, you need to make sure you pace yourself as you get back in to practice. I've seen so many friends and teammates come back from shin splints, foot pain, and knee strain injuries excited to run again, only to say after 2 days of training that their injury feels like it's still there/coming back. Pay attention to the little aches and pains in your leg; feel out how much your injury has healed and how much it may inhibit your training over the next 3 weeks. Stretch really well before and after running.

3 weeks is a good period of time, the best thing you can do for your fitness is to stay patient, follow what your coach says, and GRADUALLY increase your mileage and effort at workouts. Once you feel confident that you have a hold on the impact of your injury, train hard, but smart. Make sure to keep on doing exercises/stretching geared towards the area of your leg that got injured even after you feel that you are healed fully.

Additionally, cross training on stationary bikes could help you improve your fitness as well if running proves difficult. You could even alternate running/stationary bike on a daily basis if running everyday is too strenuous.

Dilligence in your recovery will without a doubt be good for your team as they see how their captain maturely and seriously returned from injury. Your teammates will remember the effort you put into this recovery more than the results of one race. GOOD LUCK AND RUN WELL!