Like Org said above, I don't know that he has to keep it up much longer. I think it would be enough to put up another CY or CY caliber season, then a couple of 3-5 win seasons. A 10-year stretch as the best pitcher in baseball over that period, with 50-fWAR, 2-3 CYs, and a sub-3 ERA probably does the trick.
It will help if he can play a big role in a WS win (probably won't happen) and avoid bad association of being an albatross to his team on a rich multi-year deal later in his career.