Standing in Phelps's way is a set of talented opponents—including a U.S. teammate
? Ian Thorpe
Australia, 200 free The 21-year-old—who won three golds in Sydney and has set 22 world records since 1999—is the record holder and favorite in the 200-meter freestyle. The Thorpedo could also face Phelps in three relays, with the Aussies a threat to win two of those.
? Ian Crocker
U.S., 100 butterfly Maine's first Olympic swimmer, Crocker, 21, set world records in edging Phelps in the 100 fly at the 2003 worlds and U.S. trials. Says Crocker, who could win four medals, "Michael pushes me to swim faster."
Hungary, 400 IM The 18-year-old finished second to Phelps in this event at the 2003 worlds and is stronger than Phelps on the breaststroke leg. Since 1988 Hungarian swimmers have won four Olympic medals (three of them gold) in the men's and women's 400 IM.