Phelps and his coach Bob Bowman told a news conference at the end of the U.S. Olympic Trials on Wednesday that the teenager would contest the 200 metres freestyle, 100 and 200 metres butterfly and 200 and 400 metres individual medleys.

He also plans to race in the 4x100 metres freestyle, 4x200 metres freestyle and 4x100 metres medley relays.

Conspicuously missing was the 200 metres backstroke, an event in which Phelps is ranked number two in the world and in which he placed second on Monday behind Aaron Peirsol's world record-breaking performance.

"We've decided to save the 200 back for another opportunity somewhere down the road," Phelps said.

The 19-year-old phenomenon said the decision was not made because he was tired on Monday, when he swam three events in the evening.

"Actually, the farther through the week we got, the better I was feeling and the better my lactate readings were," he said.

"It came down to the question: what is the best programme we can do? And this is the programme I feel most confident about."

Bowman added: "Physically, Michael was fine on Monday. But the following day he really felt (the impact of swimming three races in less than an hour).

"Ian Crocker (who won the 100 metres butterfly) is hard to beat under any circumstances. So we want Michael to be at his best in Athens when they swim the 100 fly, which also has relay implications."

In the 200 metres freestyle, Phelps will lock horns with Australia's world record holder Ian Thorpe and former world record holder Grant Hackett, Pieter van den Hoogenband of the Netherlands and his U.S. team mate Klete Keller.

It is entirely possible that Phelps might not even win a medal in the 200 metres freestyle, but the confident teenager said he relishes the challenge.

"It will be an honour to race Thorpe in his best event and I look forward to it."