According to Major League sources, the A's have received permission to interview Rangers' coach Don Wakamatsu for the bench coach vacancy on manager Bob Geren's 2008 coaching staff. The interview is set for Friday. Wakamatsu, 44, served as former Rangers' manager Buck Showalter's bench coach from 2003-2006 and was one of five managerial candidates interviewed after Showalter was let go.