Last week, after Jorge Arangure broke the news that Dominican prospect Rafael DePaula's MLB signing ban had been lifted, I exchanged a few "tweets" with Jorge and Keith Law, centered around my post about DePaula's consideration of Japan last summer. Sometimes 140 characters isn't enough.
@keithlaw: @npbtracker I'm not sure why no suspended player has tried Japan, or even Italy or Holland. Go make some coin and keep playing for scouts.
Practically speaking, it doesn't make sense for NPB teams to sign suspended prospects, assuming that they are a) not ready to contribute at the top level in Japan and b) only willing to sign short-term contracts. I was bullish on DePaula trying Japan last summer - with the caveat that he'd be willing to make a long-term commitment (looking back, I wasn't clear enough about this in my post). Certainly a number of Taiwanese players, and some Dominicans have signed with Japanese teams as amateurs and done well.
The Carp have an Academy in the Dominican, from which they recently brought a couple of players to Japan. Pitcher Wilfreiser Guerrero was in the Carp's Academy in 2007, followed by two years of independent ball in Japan, and has now joined the Carp as an ikusei (development) player. Dioni Soriano, another pitcher, joined the Carp last season after following a similar pattern. Hiroshima also added two pitchers as "practice" players this offseason: Juan Javier (22) and Jose Lauriano (20)*. Javier initially lied about his age and identity, claiming to be 16.
The Chunichi Dragons don't have a Dominican academy, but scout the Winter League heavily and have signed quite a few players over the last few years, including four this offseason. Unlike the Carp, as far as I know Chunichi has only signed players with at least some professional experience with MLB organizations. They do take younger guys without much upper-level minor league experience though.
Beyond that, the SoftBank Hawks showed some interest last offseason about finding an independent Dominican baseball academy to establish ties with, but I never read anything about it beyond the initial report. The Yomiuri Giants have had some success developing Wirfin Obispo, who signed as a 22 year-old and put up a solid showing last year in his first real test at the top level. Yomiuri has an academy in China but not in the Dominican.
Up to this point, the main international market Japanese teams recruit amateur talent from is Taiwan (Chen Wei-Yin, Chang Chih-Chia). My opinion is that if NPB is going to miss out on top Japanese talent, like Junichi Tazawa, the best way to stay competitive would be to sign more talented amateur players as international free agents. NPB teams will never be in the mix for the Michel Ynoa-class prospects, but could reasonably compete for players in the $300-$500 bonus range.
*Note: I guessed the spellings of Javier's and Lauriano's names, as I only had them available in katakana.