Another factor in this: Oakland is apparently eager to trade Brett Lawrie, a very comparable third baseman. If the Twins were pushing for a Plouffe trade, the immediate effect would be a buyer's market. Taking their time on moving Plouffe, assuming they want to, might well be the best tactic.
Well, on Thursday the A's did trade Lawrie, and their return from the White Sox (a pair of minor league pitchers) was regarded as underwhelming:
That is a rather modest haul for Lawrie. https://t.co/cC49nhJorC— JJ Cooper (@jjcoop36) December 10, 2015
It's certainly plausible that the Twins took a quick read of the third base market, realized that there wasn't going to be much of a market for Plouffe, and decided to try to make a virtue of necessity. Still, I suspect the Twins would be better off with Sano at third and either Max Kepler or Oswaldo Arcia in the outfield than with Sano in the outfield and Plouffe at third, even if they got zilch for Plouffe.
Here's an amusing (to me at least) sidelight to the Lawrie trade: As of now, it makes Danny Valencia the A's third baseman -- the same Valencia who lost the Minnesota third base job to Plouffe. Shuffle and deal, shuffle and deal, and the same cards keep showing up.