At the Olympic trials in Omaha, Neb., earlier this summer, Michael Phelps took center stage by giving his usual performances, smashing American and world records and swiftly touching out his contenders.

“This is all about Phelps, this is his show,” a spectator in Omaha said. Phelps, who swims with Michigan’s Club Wolverine, even broke his own world record in the men’s 200-meter individual medley in 1 minute, 54.8 seconds.

Beijing is expected to be Phelps’s baby too. In the Forbidden City, Phelps will gun for eight gold medals, which would put him one gold medal above famed American swimmer Mark Spitz, who won seven golds at the 1972 games in Munich. Phelps will race in five individual events in Beijing, including the 200m freestyle, the 100m butterfly, the 200 fly, the 200 individual medley, and the 400 IM. He holds the world record in all of them except for the 100 fly .

“Anything with Michael Phelps in it will be interesting to watch, but he’s had challenges here in the backstroke particularly and the butterfly,” Jeff Farrell, a two-time Olympic gold medalist at the 1960 games in Rome, said. But Phelps faces serious rivalry in a number of events.

The 400 IM

Ryan Lochte is one of Phelps’s closest rivals. In Omaha, the 23-year-old swimmer made headlines when he and Phelps went head-to-head in the 400 IM, considered the decathlon in the sport, since it consists of 100 of each stroke. Lochte touched Phelps out at 4:13.38. Phelps came in second at 4:13.43, considerably off the 4:06.22 world record he set at last year’s world championships in Australia.

Lochte, who swims with Daytona Beach Swimming, is no amateur. In Athens in 2004, he took silver in the 200 IM. “I think [Lochte’s] a sleeper. He came in second for just about everything, and you never know,” a professor at John Jay College of Criminal Justice of the City University of New York’s Department of Physical Education and Athletics and a member of the U.S. Masters Swimming All-American Team, Jane Katz, forecasts.

Laszlo Cseh of Hungary is a contender in the 400 IM, too, and could snatch the gold from the Americans. In Athens, Cseh took third in the event at 4:12.15, with Phelps and American swimmer Erik Vendt taking first and second.

The Fly

Ian Crocker, 25, stands a good chance of winning gold in his forte, the 100 fly. Crocker is a close nemesis of Phelps, their rivalry the subject of a 2005 documentary, “Unfiltered.” But Crocker’s biggest enemy might be himself: The swimmer seemed emotionally crushed after disqualifying at the 400-meter medley relay at the U.S. Championships in 2007. Crocker — an alumnus of the University of Texas’s Longhorn Aquatics — is quiet, introspective, and has written about his battle with depression. His Web log is on swimroom.com.

The Backstroke

Aaron Peirsol, another Longhorn Aquatics success story, has a chance of touching out Phelps in the backstroke. Peirsol holds a litany of world records in the backstroke, took gold in the 100 backstroke at the 2007 World Championships, and won three medals in Athens in 2004, including the 100 backstroke. One of Peirsol’s rivals is Lochte, who came in at a close second in the 200 backstroke in Omaha.

Splash and Dash

Cullen Jones is a fast-rising star in the 50 freestyle and 100 free sprints. The Bronx native is the third black swimmer to make the U.S. Olympic Team, after Anthony Ervin in 2000 and Maritza Correia in 2004. In Beijing, watch for Jones in the 100 free and in the 400 free relay.

“I think he can be just as good in the 100 as in the 50, so it didn’t surprise me that he made the 100,” the head coach of North Carolina State University’s swimming team and one of Jones’s coaches, Brooks Teal, said.

If Jones takes gold in the 100 free, he will join a fraternity of swimming legends, including Alex Popov, Matt Biondi, Spitz, and Rowdy Gaines.

The Breaststroke

Kosuke Kitajima of Japan is expected to sweep most, if not all, of the breaststroke events, including the 100 breaststroke and 200 breaststroke. But American Brendan Hansen is top breaststroker, too, and is expected to medal in the events.

Outside of the lane, men’s swimming serves up an inspirational story with Eric Shanteau. The 24-year-old swimmer plans to race the 200 breaststroke even after being diagnosed with testicular cancer in July.

The 200 Free

Phelps’s rivals go beyond American soil. Pieter van den Hoogenband, the Dutch swimmer and a triple Olympic champion, could touch Phelps out in the 200 free. Other top international swimmers to watch are Grant Hackett of Australia, Alain Bernard of France, Fillippo Magnini of Italy, and Tae-hwan Park of South Korea.

Relays

The rivalry between the French and the Americans transcends culture and cuisine in Beijing’s water cube. One of the most exciting relays is the 400 free. “France will give the Americans the hardest time, and they have Alain Bernard, the world record holder on the team,” Patrick Cantrell, head coach for Masters swimming at Asphalt Green, said. Historically, the Australians have been strong, too.

Ms. Wu is a contributing writer for Swimmer magazine.