For Phelps and more than 800 others, spots on the U.S. team for the world championships in Rome this month are up for grabs.

The 14-time Olympic gold medalist is competing in four events, starting with the 200-meter freestyle and 200 butterfly tomorrow. Phelps holds the world record in both.

It is his biggest meet since his return from a nine-month break after the Beijing Olympics that included a three-month suspension for appearing in a photograph with a marijuana pipe.

"I'm back to where I want to be and probably a little faster," he said yesterday before practice at the Indiana University Natatorium pool, where he made his first U.S. Olympic team as a 15-year-old in 2000.

After winning a record eight gold medals in Beijing, Phelps is remaking himself with a focus on the shorter events as he heads toward the 2012 London Olympics, his final Games before retirement.

He has dumped the 200 and 400 individual medleys and the 200 butterfly from his Beijing program.

"I don't want to classify myself as a sprinter," Phelps said. "I always thought swimming the shorter events would be easier. It's not. It's a big thing I've had to get used to."

He is also experimenting with a new freestyle stroke, using a windmill-like motion mixed with his normal bent-at-the-elbow technique.

Phelps will swim the 100 butterfly Thursday and the 100 free Friday.