Free-agent quarterback JaMarcus Russell has admitted that he tested positive for codeine after the Raiders selected him with the No. 1 pick in the 2007 draft. "I missed all of training camp, so I didn't get tested when all the other guys got tested," Russell told ESPN's Colleen Dominguez. "I had a prescription from a doctor, but it wasn't the team doctor." Russell said he has used codeine without a prescription but scoffed at reports that he had a drug problem. He added that the allegations of drug use stem from that positive test and said he has not used codeine in three years.