If it appears that Masahiro Tanaka isn’t lighting up the radar gun like he did during his terrific rookie campaign, the Yankees right-hander is armed with a good explanation, and it’s one which he says is unrelated to last year’s elbow injury. Tanaka revealed on Wednesday that he has decided to throw his two-seam fastball more this spring, a pitch that has less velocity than his four-seamer but adds downward movement.