If Matsui heads to the DL, the amount of injuries suffered by the Yankees this year would almost be comical... but not quite. The Yankees need his high average and OBP, look at his stats this year:

from: http://newyork.yankees.mlb.com/news/article.jsp?ymd=20080626&content_id=3010709&vkey=news_nyy&fext=.jsp&c_id=nyy

Ignore his unflattering RBI's and Runs because, if he is able to maintain his batting average, and continues to hit in the 5-spot, either he accumulates RBI's or the Yanks are in trouble.

"Girardi acknowledged that the team will discuss the option of placing the designated hitter on the disabled list when it returns to New York."
from: http://newyork.yankees.mlb.com/news/article.jsp?ymd=20080626&content_id=3010709&vkey=news_nyy&fext=.jsp&c_id=nyy

As fans, we can only hope that:
a.) he doesn't go on the DL
b.) he doesn't play injured, hurting his output

If he is as hurt as it looks, looks like either option is a possibility...

from: http://yankeebible.blogspot.com