Dodgers reliever Ronald Belisario missed all of last season because of visa problems in his native Venezuela. He admitted Wednesday that a positive test for cocaine kept him from obtaining the necessary paperwork that would have allowed him to enter the United States. Belisario, who must serve a 25-game suspension at the start of this season for failing to comply with baseball's drug policy, said he used the drug only once. "I don't have a problem with any drugs," he said. "It was a one-time thing."