Team Green Richmond Racing Kawasaki's Darcy Lange will sit out the San Francisco round of the Amp'd Mobile AMA Supercross Series after suffering a grade three concusssion last weekend at Anaheim 2. In an email from team manager Billy Whitley today, the team announced the decision, adding that it was a difficult one.  Lange will make his return to the Western Lites series on February 4 at Anaheim 3.