Should Sox be worried about Dice-K?

Are the Red Sox worried about Daisuke Matsuzaka? Should they be? Does the WBC deserve all the blame for Dice-K's spring struggles? Tom Verducci with some history:

    The Red Sox, however, better hope it is only the WBC that caused Matsuzaka's fatigue. When Boston placed him on the disabled list, I thought not only about the WBC, but also about a story I did about Matsuzaka prior to the 2007 season, his first in the majors after a distinguished, and grueling, career in Japan. What stuck with me is how both the Red Sox and Scott Boras, the agent for Matsuzaka, were concerned about the ominous track record of Japanese starting pitchers when they jump to the big leagues. Both the club and the agent knew about a pattern in which Japanese starters have success in the majors for a year or two, but wear down in years three and four.
    "The greatest concern is ensuring his health," Boras said then, "not just this year but over the life of the contract and beyond. The history of the Japanese [starting] pitchers who have come here is concerning."

    The Red Sox, who study these things exhaustively, correlated the decline to age, with the dropoff occurring in the early 30s. But general manager Theo Epstein, when asked about the trend of third and fourth year declines, said, "We may be talking about a similar thing, just measured differently."

    Matsuzaka was 26 when he joined the big leagues, the same age as when Hideo Nomo made his jump. The other relevant comparisons are Kaz Ishii (28 when he joined MLB), Hideki Irabu (28) and Masato Yoshii (33).

    The biggest concern for such a track record is the difference in how pitchers are used in Japan and in the majors. Matsuzaka pitched every sixth or seventh day in Japan in a shorter season, but his individual pitch counts wouldn't be allowed in America. He threw, for instance, 250 pitches in a high school game, 189 pitches on Opening Day 2003, 160 pitches in his second start of 2005 and 145 pitches in his penultimate start before signing with Boston. Perhaps most ominously, Matsuzaka threw 588 innings as a pro in Japan as a teenager.

    As former Red Sox teammate Curt Schilling said back in 2007, "He is a big league ace in the making. The question is, does he throw his last pitch at 31 or at 39?"

(You should read the whole article, as I've left out some good stuff.)
If Dice-K throws his last pitch at 31, the Red Sox will be disappointed, because he turns 32 in September 2012, and if he throws his last pitch before then, he'll likely have missed some significant stretches of time already.

When the Red Sox invested $103 million in Matsuzaka, they took a huge gamble, a gamble they -- with all their affection for objective analysis -- could only begin to measure. Why? Because there had never been a Japanese pitcher with his track record in Major League Baseball. Analysis doesn't work without data, and the relevant data on Dice-K fell well short of what any good analyst would have craved.

So you do the best you can, and you guess a little bit, and you spend the $103 million because you've got it and because you really, really, really want to beat the Yankees.

So far, so good. In his first season, Dice-K won 15 games in the regular season, and a World Series game. In his second season, he went 18-3 (despite leading the AL in walks). But suddenly 2012 seems like a long ways away.