Filippo Magnini, the two-time world champion? Gone. Nathan Adrian, the rising American star who took both sprint events at the recent nationals? Gone.
Still standing, and swimming in the final tonight in the men's 100-meter freestyle, is none other than 21-year-old David Walters, who had the sixth-fastest qualifying time at the world championships.
He went 47.92 seconds Wednesday night in the semifinals, not as fast as his 47.59 in the morning prelims (just off Michael Phelps' American record, 47.51) but good enough to make the final eight.
"The 200 free is my better event, but now that I'm getting a top-eight swim out of my 100 makes me feel like my time here was worthwhile," said Walters of Yorktown, Va. "I've never really thought about the  race too much. I've always thought about the 200 more.
"I kind of have that naive type of inspiration going on."
He qualified for the worlds by placing second in the 100-meter free and 200-meter free at the 2009 nationals in Indianapolis. He took home a gold medal at the 2008 Olympic Games in Beijing by competing on the 800-meter free relay in the preliminaries and helping the U.S. squad qualify for the finals.
Walters, who battled strep throat during training camp before the worlds, rallied after failing to qualify for the final of the 200 freestyle here.
"I had an awful 200 free, so I went to the hotel spa, had a cup of coffee, [saw] beautiful women," he said. "Felt better about myself. Had to take a time out. Eat grapes and drink coffee.
"You can leave on that note or get a fresh start and make something else out of it. You don't want to let the free trip to Rome go by."
Walters will have to swim a smart, tactical race against a star-studded field. The final tonight is shaping up as a two-man duel between Frenchman Alain Bernard and Brazilian Cesar Cielo. Bernard led the semifinals Wednesday with a time of 47.27 seconds. Cielo was second in 47.48 and Stefan Nystrand of Sweden third in 47.53.
"I know I've got a great back-half race," Walters said. "I'm not intimidated by people going out about a second faster than me.
"It is a little mind-boggling to be out slower than everybody, but I'll catch up to them fast."
The Associated Press contributed to this article.