A very high risk, high reward player.
If he is healthy (which I seriously doubt), he should at least be the No. 3 in the Sox starting rotation. No way I see him being used as a MR. That would be crazy.
In the unlikely scenario he does stay healthy all year then 16-17 wins, 170k's and a sub ERA of 4.00 would not be unexpected.
To me, what's more likely is starting only a handful of games all season.
If you're drafting right now or if he pitches in ST then he is definitely worth taking a flyer on. If we don't see him before the season starts, in a normal sized league, I wouldn't waste a roster spot on him.
When you're right no one remembers, when you're wrong no one forgets - NZF