What I'm about to say has nothing to do with his ability. That said, there might be a short term increase still out there, but a sustainable $400 base auto isn't likely. Just purely based on the number of cards printed, there's no way. Say he turns out Pujols great, even at the top of the Pujols...
This would be a sad way to go out if he doesn't come back. I understand not liking the Yankees, but I've never understood the hate for Rivera and Jeter who are career Yankees.