Over time, any athlete playing a contact sport (a game in which physical touch between opponents in some form is allowed; like basketball, football or boxing; golf and tennis, paradoxically, are non-contact sports) will acquire some bumps and bruises. You catch an elbow in the back while going for a rebound. You get fouled on a drive, fall hard, and you hip feels tender for severaldays.
These are examples of being “hurt.” Hurt is what you’ll feel as the wear and tear of a physical game adds up day by day. Hurt is something you feel, and figure out a way to overcome those feelings of weakness so you can perform at you best level. You play through “hurt.”
A broken leg, on the other hand, or a pulled hamstring, or a fractured wrist, are all examples of injuries. An injury requires a hospital visit, probably some form of medical body scan, and a doctor’s order to not do something for some specified period of time. Playing injured is reserved only for extenuating circumstances — like, say, Game 7 of a Playoff series — AND will always be up to the discretion of the doctor, who can veto your heroic ideas.
Playing hurt will help you — you learn to focus on the task at hand, blocking out your feelings in favor of what needs to be done.
Playing injured is not recommended. Playing injured can make your injury worse and shorten your career.
Listen to your body. It won’t lie to you.