Few setbacks are as discouraging as a physical injury. Whether major or minor, it can be utterly defeating to no longer be capable of what you once were, even if it is temporary. The fortunate part is that, far more often than not, it is temporary. Better yet, you can continue to become even more fit while injured!
Injuries come in all shapes and sizes; some may require the immobilization of a joint or limb, while others do not. Some may incur a substantial amount of pain; others not so much. Some may last a long time; others may be short. If an injury is severe, it may require near absolute rest, rendering the prospect of training virtually impossible. However, in the vast majority of instances, this is not the case.
Consistency and proper modification is the most effective strategy for minor to moderate injury management. A certain exercise may be symptomatic, but that does not mean you cannot continue to develop the surrounding musculature. For example, the strict press may cause pain in your shoulder. With some experimentation, you find the seated tempo dumbbell press to be pain-free. This is an opportunity to maintain and even progress your fitness while properly managing your injury. In time, you may discover even more opportunities.
If you are contending with a painful injury, maintain your exercise routine and modify to avoid symptoms while still training the affected area. Physical setbacks may be limiting, but in time your injury will pass. Once that obstacle has been eliminated, your attention to detail and forethought will be rewarded when you continue to get stronger!