Why did the Yankees sign Kevin Cash when Josh Bard was available?

Yes Bard is always hurt, but atleast he's shows some great numbers when healthy (.338 avg, .406 OBP in 93 games in 2006 after being traded from Boston). Kevin Cash on the other hand, is awful. He can't hit, no minor league numbers either. Nothing except that HR last yr in the postseason. Is there a defensive upside to him that I don't know?