With any sport there is always the risk of injury.  This is especially true the farther you climb the ladder of success in your sport.  You can’t expect to train at the level of intensity that it requires to be elite and never get injured.
Yesterday I worked out with Brandon Phillips and Derek Robinson at Crossfit Bound.  Both of these men have found themselves behind the 8 ball with different injuries.  Derek is just coming off surgery to his knee and BP has always had shoulder issues.  Both of them however recognize the value of training around those injuries.  The idea that injury has to bring a halt to your training is a silly disguise for laziness.
There are multiple ways to train around injury especially while rehabbing that injury.  Derek could not put pressure on his knee in flexion.  So what did he do?  Ring pullups, DB overhead work, muscleups, and close grip bench press.  He could take the time to rehab his knee and stop training altogether.  However, D-Rob just like BP, are  competitors and this background doesn’t allow for laziness.
No matter your injury (for the most part) there are always ways to train around it.  You will only make a injury worse by losing what valuable work you could be doing during that injury.  Find a way to train.  Find a way to work around something that is nagging you.  But always train when its time train.