In Michigan you can't see a PT for treatment without a prescription. I thought that was the way it is everywhere but apparently not.I have never heard of that cracking in anyone or felt such a thing.
Maybe impingement up at the top rib. Shoulder joint can also take a beating, especially if the player has an 'over the head' pre-motion. Not good. See the doctor and stop pitching like others have said.
You can ALWAYS see PT directly if you pay for it yourself. Nowadays folks do that because the PT is sports minded and the doctors like to operate on everyone.....