At 30, Johnson still looks like a football linebacker. As well he might: his dally workout includes several repetitions of bench-pressing close to 400 pounds. Since re-entering competition the day after his suspension ended in September 1990, Johnson has been closely scrutinized for performance-enhancing drugs. In the last month, he’s been tested at least three times. Johnson says he’s already achieved his goal simply by being in Barcelona. But if he stays clean, Johnson could earn more than a medal and leave the ghost of Seoul behind at the starting line.