PHEONIX, Arizona (Kyodo) -- The Arizona Diamondbacks on Friday announced the signing of Japanese right-hander Shumpei Yoshikawa to a minor league contract.
Yoshikawa was a top amateur prospect and expected to be a high selection in Nippon Professional Baseball's amateur draft in October.
According to his corporate league team Panasonic, the 23-year-old Yoshikawa violated Japan's amateur baseball federation rule requiring players to have their player registrations deleted before they enter into a pro contract.
It is said that Yoshikawa began contract negotiations with the Diamondbacks before filing the proper documents and was in touch with the American club even before the end of the recently completed intercity tournament.
The Diamondbacks' public relations officials declined to comment.
Last December, the Diamondbacks signed Japanese pitcher Yoshihisa Hirano to a two-year, $6 million free-agent contract.