Melky Cabrera would give Minnesota a center fielder to replace Torii Hunter if he bolts. The Yankees could then offer the Twins Phil Hughes or Ian Kennedy along with a second prospect.
If Melky and Kennedy plus a prospect can land Santana, I can't see why the Yankees wouldn't do that, even if only for the opportunity to get a leg up on signing baseball's best pitcher to a long term deal. But I would assume it would take a lot more. Lots of names are being tossed around along with
Philip Hughes, particularly
Robinson Cano, names that are most likely the premium the Twins would demand and perhaps a deal-breaker for the Yankees.