The first hope is that he can stay healthy. Secondly he needs to clean up his fielding as I don't believe the Twins anticipated his -dWAR when they signed him.
As for his bat, it seems to play better when others are better around him. Having a stronger hitter behind him would help (like it would anyone), but as long a Rocco goes with his typical right-left-right line-up, it would be huge boost to Donaldson if Kiriloff, Polanco or perhaps Kepler got *really* hot.
That plus a bit more "luck" on balls in play would be nice!