The letter, sent by MLB to the Rakuten Golden
MLB spokesman Pat Courtney confirmed Sunday that the league had sent the letter and requested those assurances. It was not immediately clear how Rakuten might respond.
Rakuten might have gotten three times more money from making Tanaka available under the old posting system, in which MLB teams bid to acquire exclusive negotiating rights from Japanese clubs. In 2011, the
Under the new system -- approved by NPB clubs over Rakuten's objection -- the posting fee paid to a Japanese club is capped at $20 million, and the player can negotiate with any and all MLB teams.
At a news conference last week, Rakuten President Yozo Tachibana called the new system unfair but said Tanaka would be allowed to leave for MLB. Tachibana also said Tanaka wanted to donate to improve the Rakuten stadium, including its facilities for players and fans.
However, the new agreement between MLB and NPB expressly prohibits a Japanese club from getting any value other than the so-called posting fee, directly or indirectly, including through the player. MLB is concerned about the appearance of a link between the purported donation and Rakuten's decision to let Tanaka go.
The existence of the letter was first reported by Sponichi, a Japanese newspaper.