The Diamondbacks appear ready to open the checkbook for Japanese right-hander Masahiro Tanaka, the most coveted free agent on the market this winter. Japanese newspaper Nikkan Sports reported Saturday that the D-backs have offered Tanaka a six-year deal worth 10.5 billion yen, roughly $106 million. The paper also said the Yankees, Dodgers, Cubs and White Sox have made offers in that same range, and those teams could be emerging as Tanaka's final five. No contract length or terms had previously surfaced.