When the MLB strongarmed the NPB into this new posting system, we heard a lot of arguments as to why Tanaka would still be posted. 20 million dollars is a ton of money, even if it isn't the perhaps 75 million that the Golden Eagles were on track to get. However, as of late, the President of Rakuten hasn't really given an indication either way, with recent reports (since refuted in large part due to Brett at Bleacher Nation) saying he was NOT going to be posted. No one knows at this point. However, I'm certain that I wouldn't post Tanaka if I were in charge.
Pay me now or pay me later
What is the benefit to Rakuten if they post Tanaka this season? Surely, they get 20 million dollars. They also save the salary they would pay Tanaka, which is $8 million dollars. Let's say that a post in 2013 nets Rakuten $28 MM.
What is the benefit if they post Tanaka next season? I'd bet that even if Tanaka had a much-reduced effectiveness, he'd still get a $20MM posting fee. He'll still be entering his age-27 season, prime pitching years. With the exception of perhaps a TJS or other catastrophic injury (which he'd have to suffer in the year he's least likely to actually get it), The only cost in future earnings is the $8 million they'd have to pay him 2014. Do you know how I know that's a good deal for Rakuten (besides the fact that he's the best player on a defending Nippon Series champion)? Because they offered him that money. They could have paid Tanaka essentially whatever they wanted. Tanaka can't retire like Nomo did and defect, so he'd have to take the money. It's very hard to get actual payroll data for teams in the NPB, so I admit to some speculation on my part here, but if the question is simply "is Tanaka worth $8 million to the Eagles this season," the answer is almost certainly yes.
There's a time value of money aspect to this deal, but even if we took inflation to be 5%, that's only another million dollars that Tohoku Rakuten "loses" by waiting a year. I fail to see how the Golden Eagles post Tanaka in this situation….unless, of course, there are other motivations besides money. Reputation has a chance to supercede sound financial advice, but really, how often does that happen?