Best of luck to the fellow, it is nasty. Almost happened to me once, got to pleurisy but caught it in time not to progress to pneumonia.
Speaking to doctors in the hospital about it, they told me that I had a cold, but didn't rest properly and just riding my cough and infection out while still working wasn't being tough, it was in fact dumb.
Warning to everyone, not just athletes, if you are not well, rest until you get well and ease into it, don't push too hard or you will go backwards...
Athletes, by all accounts are more suseptable because they use almost all of their energy reserves playing and training, this is why proper recovery is paramount!