The Major League Baseball Players Association is threatening to block a new posting agreement over the Hokkaido Nippon Ham Fighters' posting fee, the New York Post reported on Wednesday.

According to the report, the union is unwilling to sign off on a new posting agreement because it includes a clause that allows Nippon Ham to claim a $20 million posting fee for the 23-year-old Otani, who will only be able to earn a fraction of that amount should he sign with a major league club this winter. That imbalance is ostensibly the union's issue with the clause.

The combination of MLB's new labor agreement, that severely curtails the amount of money teams can spend on overseas players under the age of 25, and MLB's proposed new posting system would see Japanese teams posting young superstars in the future limited to a transfer fee of around $1 million. The proposed posting deal will change from a fee set by the posting team (currently up to $20 million to a flat percentage of a player's contract).

Yet, as previously reported by Kyodo News, the Fighters had already negotiated a deal to receive the same $20 million that they would have received had Otani been posted a year ago.

The New York Post report indicated that the MLBPA would be happier to negotiate through a union-certified agent, but there is no indication that Otani has yet to select an agent.