Can Kazumi Saitoh be Posted This Year?

I think you have a fundamental misunderstanding of how the Posting System works. There is no minimum service time to be posted. 9 years (being registered on the top team) is necessary to become free agent, but not for being posted.

There is a correlation between posting and reaching free agency. Teams want to hold on to stars as long as they can, so if they're interested in selling a player to an MLB team, then the year before the player becomes a free agent is the optimal time to do so (as teams don't get compensation for free agents who go to the MLB). But assuming that teams are developing stars for the purpose of selling them to MLB teams is a fallacy created in the heads of the North American press (who don't let the need for research and/or facts get in the way of a good ego-centric story) because greed is the only motivation that they understand.

Please use the search box at the top of this page. "Posting system" (with quotes) is a good term to start with in researching this subject. I know that some people think I'm a jerk for asking people to research things like this on their own (as opposed to just telling them what they want to hear), but those who (even grudgingly) take my advice tend to appreciate it in the long run.