I have misread the Tigers, and I'm really not sure what this means. While the Tigers probably expected more out of Fielder, his presence was a big reason Cabrera has been the best offensive player in the American League the past two seasons. Essentially, I don't believe the Tigers would have won the division the last two seasons without Fielder in the lineup.
I could see the Tigers wanting to move Cabrera back to first and upgrade defensively at third, although Cabrera actually had a pretty good defensive season there, certainly better than expected. But I really didn't expect them to deal Fielder, especially for Kinsler.