First off, I believe the Tigers should go the declined option, offer arbitration route with Edgar Renteria. If he accepts, you've got a guy who should be a solid option on a one year deal. If he declines, take the draft picks, run, and maybe try to sign this guy:
Mark Ellis has been a second baseman for a while, but he only moved there to accommodate Bobby Crosby back when it was thought he would be a star okay shortstop. Ellis is among the top defensive second basemen in the game, so it's only a matter of if his arm could handle short. Last year, A's fans gave him a 55/100 ranking for his arm strength, and 92/100 for accuracy. I haven't been able to watch many A's games this year, but it could be worth a thought.