Yeah, I think 4 WAR is probably a bit optimistic. I'd be worried about health, but I could toss that disclaimer at all pitchers (and, yes, I saw the link above - but I'm done trying to figure out pitcher health...it's more of a crapshoot than anything). His performance wasn't a fluke, even if the actual result in terms of runs allowed was a little better than expectation. Probably best to just make your best estimate at pitcher war and take off 20% (or some more scientific figure) off the board due to health.