Gold Coast - Record-breaking Olympian Michael Phelps will swim his first international meet since coming out of retirement at this week's Pan Pacific Championships as he seeks a return to winning ways.
Phelps, 29, the 18-time Olympic gold medallist, will take his quest for form to Australia's Gold Coast after he ended this month's US Championships with a couple of near-misses but no wins.
Despite this, Phelps made the powerful 60-strong American team for the Gold Coast meet, just four months after ending a 20-month retirement which began after the London Olympics.
Australia's James Magnussen will resume his sprint rivalry with Nathan Adrian, part of a heavyweight US team also including Ryan Lochte, Missy Franklin and Katie Ledecky.
But attention will inevitably focus on the continuing comeback of Phelps, the greatest Olympian of all time who will contest up to five individual events.
At the US titles Phelps botched a turn in the 100m free to finish seventh, was out-touched by a fingertip in one of his signature events, the 100m butterfly, and finished sixth in the 100m backstroke.
But he staged an exciting battle with Lochte in the 200m individual medley and finished just 0.05sec behind the world record-holder in the event where he has won three Olympic golds.
"I am taking it a lot slower now than what I did before, because I do understand that I need to give my body time to get back and build up to where I want to be," Phelps said this week.
"I can't just expect to do everything I want from the get-go.
"Being able to have a year-and-a-half off, I've been able to learn a lot about myself and I still have that competitive side."
The four-day meet at the new Gold Coast Aquatic Centre in Southport is key preparation for next year's world championships in Kazan, Russia leading up to the 2016 Rio Olympics.
Lochte, who long swam in the shadow of Phelps but who counts an impressive five golds among his 11 Olympic medals, has endured a difficult year of his own, missing training time after tearing a ligament in his knee.
"My confidence wasn't there because I always relied on my training, but this year I haven't done that training," he said.Meanwhile there will be big local interest in world and Commonwealth champion Magnussen's showdown with his London Olympics conqueror Adrian in the 100m freestyle.
'The Missile' went down to Adrian by a mere one-hundredth of a second in the 2012 London final, following his win in the event at the world championships the previous year.
Magnussen has been troubled by a degenerative back condition, but scans and treatment have cleared him to compete on the Gold Coast.
"It (back) was pretty dodgy when I got back from the Commonwealth Games," Magnussen told reporters on Tuesday of the Glasgow event.
"But we have been working really stringently on it and I am doing the best I can to be as close to 100 percent that I can."
Magnussen will lead an Australian team which topped the Glasgow Games pool tally with 57 medals (19 gold, 21 silver, 17 bronze) last month.
Ledecky, one of 17 Olympic gold medallists in the American team, comes to Australia following her third world record of the year, in the 400m freestyle at the US Championships.
She also holds the 800m and 1500m freestyle world marks.
Australia's world champion sprinter Cate Campbell, fresh from her Commonwealth Games 100m freestyle gold over her sister Bronte, will be up against American four-time Olympic gold medallist Franklin.
South Africa are not sending their two Olympic champions, butterflyer Chad Le Clos and breaststroker Cameron van der Burgh, but South Korean Park Tae-hwan, a dual London Olympic silver medallist, is in the mix for the freestyle events.
The 12th Pan Pacs will also feature swimmers from Canada, Japan and 14 other nations.