According to this tweet from MLB.com Twins beat reporter Rhett Bollinger, Terry Ryan has said that Tsuyoshi Nishioka will see some time at third base this spring as he prepares for a utility role with the Twins. Earlier this week, Rob Antony mentioned that he sees Nishioka and Alexi Casilla competing for the starting job at second base, which could mean that spot isn't quite as open as we thought. It could also mean that the Twins are trying to maximize Nishioka's skills in order to make him as versatile as possible.
With Luke Hughes off to a slow start this spring as a result of his shoulder injury (which is apparently just a strain), Trevor Plouffe would seem to be the only player in camp who could both go north with the Twins and backup Danny Valencia at third base. But Plouffe is seemingly pegged for the outfield, so it makes sense that somebody would be groomed to at least be available to play third base.
My biggest questions for Nishioka at third base will be in terms of his responsibilies, footwork, and arm strength. Both second base and shortstop require vastly different things from the players manning those positions compared to third base. And while proper footwork will help Nishioka get the most out of his throws, we saw last season that the ball wasn't really on a laser coming out of his hand.
By the time spring training ends and the 25-man roster is finalized, it would surprise me if Nishioka was the backup third baseman. Hughes should be fine and ready to go by that point, and I have to believe that Plouffe might still have an advantage at that position as well.
What I have no doubts about, at this point, is that Nishioka should be preparing for a utility role. I just see it as a backup in the middle infield.