why did he even mention he is a 5.0? agree it is unrelated.
What do you mean it needs to crack? Like cracking knuckles or a neck?
I'm not sure that it is completely unrelated, though it probably isn't the best way to describe hitting style or the potential for overuse. I tend to believe that 5.0s are swinging and hitting harder than lower level players, though that isn't always the case.
You should rest your wrist, perhaps ice it after play, and then do wrist exercises. I've been rehabbing my wrist. I do circles with the wrist and warm it up before doing exercises with light weight to strengthen my forearm and hand. I have a short dowel with a cord through it to which I attach a weight, which can be used to work the hands and forearms. I also use a racket to practice isolated pronation and supination.
Afterwards, I stretch my wrist gently, both by pushing the palm towards my forearm and pulling my fingers back towards my forearm. Then I massage my forearms.
If the pain persists, you might have to stop playing for a while and think about seeing a doctor. Del Potro has been out for about a year with a wrist injury, so take it seriously.