Michael Phelps has withdrawn from one of the three events he planned to compete in at his eagerly-anticipated return to competitive swimming.
Phelps had entered the heats for the 50 metres freestyle, 100m freestyle and 100m butterfly at the three-day US Grand Prix meet in Mesa, Arizona, starting on Thursday.
But the 28-year-old, who had retired after the 2012 London Olympics only to announce his comeback last week, told a news conference on Wednesday that he was cutting back to two events.
"I'm scratching from the 100 freestyle," he said.
Phelps evaded questions about his long-term goals, but did not rule out the possibility of competing at the 2016 Olympics in Rio de Janeiro.
Phelps already has a record 18 Olympic gold medals and even below his best, he would be a strong contender to add to his tally just on the strength of the U.S. relay teams.
He has swum in each of the three relay events at the past three Olympics, collecting seven golds from the team races.
Phelps entered a total of eight events at the 2004 Athens Olympics, then again in Beijing in 2008 before dropping back to seven for London.
His long-time coach Bob Bowman has already said Phelps would almost certainly have a reduced workload in the future although neither would specify which events they had in mind.
"I always have goals and things that I want to achieve and I have things that I want to achieve now," Phelps said. "Bob and I can do anything that we put our minds to.
"That's what we've done in the past so I'm looking forward to wherever this road takes me and I guess the journey will start tomorrow."