Let me preface my theory--I didn't see him pitch last year and I haven't seen him this year. But I have watched a lot of pitchers over the years run in to this. Never seen one hung out to dry week after week though. I am guessing he's got what I've always heard called "dead arm" or "tired arm." What happens is the shoulder ligaments don't tear, but stretch, like an old rubber band. There's no real pain, but the strength just isn't there anymore, and its hard to detect. First time I heard of this (trying to access through the cobwebs now) was Mike Scott back in the late 80's. It used to be talked about a lot, but I haven't heard it mentioned much in recent years. At any rate, his decline late last year and flop this year meet the symptoms. Or maybe its something else completely.