I think the question of who may bat behind Sano will be solved pretty soon. Yes, Mauer has elite defense at 1st but Vargas and Park are both very capable at First Base. I think Mauer either turns into a doubles machine with RISP or the FO starts looking in another direction. I love it when Mauer plays first because I don't worry about balls getting by him. But, at the plate balls seem to get by him a lot. By the way, I just took a look at Joe's WAR and he is just under 2 for the last three years. Which puts him somewhere between solid started and role player, according to FanGraphs.