Jesus Montero has never been seen as a strong defensive catcher, and his performance as a rookie last year—seven passed balls and 19 wild pitches allowed in fewer than 500 innings; a 17% success rate throwing out stealers—did nothing to allay those concerns. With catcher Mike Zunino, Seattle's top draft pick last June, charging up the system, and very little chance the Mariners will contend in the AL West, the team needs to use 2013 to learn what it has in the 23-year-old Montero. He needs to be given most of his playing time behind the plate to either improve his skills or make it clear that he can't. Because of Montero's size (6'3", 230 pounds) and lack of speed, his only options aside from catcher are first base and DH; moving to either one would be as extreme a shift as you can make in positional value, on the order of 15 runs a season, or 15 wins in a 10-year career. The Mariners have to be sure Montero isn't a catcher before they move him to DH, and his 2012 workload behind the plate (55 starts) won't be enough to make that determination.