Junior welterweight Ryan Martin (22-1, 12 KOs), 25, of Chattanooga, Tennessee, has tested positive for a banned substance -- exogenous testosterone -- in a drug test conducted by the Voluntary Anti-Doping Association as part of the WBC's Clean Boxing Program around his participation in the World Boxing Super Series, WBC president Mauricio Sulaiman told ESPN on Wednesday. Martin suffered a seventh-round knockout loss to Josh Taylor in a one-sided fight on Nov. 3 in Glasgow, Scotland, and came up positive in a scheduled test after the bout.