Injuries and pain are part of training. You are going to have them. Should you still train when you have them? Yes. You should work around them. If you are is injured, you still have the other one. If you leg hurts, work your upperbody. There is always something you can work on. In today's time, guys use hurt fingers and toes as an excuse to no train. So, ignore the pain and work around your injuries. There is no excuse to not train.