IMO, this is just further proof that some guys are, in fact, injury prone, and not merely the victim of bad luck. If it happens 4, 6, 8 times, it's not a fluke thing; there's some inherent flaw in the person's genetic makeup, and that's not something you can escape with any amount of conditioning/treatment/etc. (Though it can certainly be called "bad luck" to end up with that genetic makeup in the first place, but that's not the point.) Rob Williams is injury-prone, period. He'll probably never come close to playing a full season.