(Chicago, IL) -- As the sweepstakes to land prized Japanese pitcher Masahiro Tanaka heat up, the Chicago Cubs seem to be making the most noise. The Cubbies have reportedly become the first team to make an official offer to the 25-year-old right-hander. Per new posting rules, MLB teams have until January 24th at 5 p.m. Eastern to sign Tanaka. Multiple industry sources indicate that the Cubs are the favorites to land him. Japanese news service Nikkan Sports reports that the Yankees, Dodgers, Diamondbacks and White Sox are the others. All offers are said to be over six-years, 100-million-dollars.