Sydney - Grant Hackett on Thursday said making the Australian team for the world championships would be like winning Olympic gold as he prepares to make his competitive return after seven years out of the pool.
The 34-year-old walked away from the sport in 2008 after winning the 1500m freestyle at both the 2000 Sydney and 2004 Athens Olympics, and claiming four world titles in the event. He won silver in the event at the 2008 Beijing Olympics.
Hackett, whose life later ran into problems, with a messy divorce and allegations he smashed up his Melbourne apartment, returns on Friday and has entered in the 100, 200 and 400m freestyle events at the nationals in Sydney.
"If I made the Australian team it would feel like winning an Olympic gold medal," he said ahead of the Australian trials for the world championships in Kazan, Russia later this year.
"(But) I never thought in a million years I would qualify for the team. It was just to see where I was at, if I want to go another six or 12 months and actually be competitive.
"I don't have expectations and I have consciously approached it like that."
As a former leader of the Australian team, Hackett said he hopes his return has a positive effect on the country's younger generation of swimmers.
"That's the point of being a part of Australian swimming and the Australian swim team is that you want to see everybody swim quick," he said.
"If me coming back into the sport for my own reasons actually lifts the younger competitors and see them get that little bit extra out of themselves, then my job is done."
Last year the former 1500m world record-holder underwent rehab in the United States after seeking help for an addiction to sleeping pills.
He is now back under his old coach Denis Cotterell and said the upheaval in his personal life led him back to the pool, but he was a different swimmer the second time around.
"I don't have expectations like I did before and I sort of reserve the right to pull out at any time," he said.
Dual world champion James Magnussen said he was under no pressure heading into the trials despite a controversial coaching switch.
Magnussen said he does not know how fast he will swim at the eight-day meeting after overcoming a back injury and tackling a different training programme under new coaches Mitch and Lach Falvey.
But he said he had no regrets as he looks to recapture his national 100m title, despite Australian team coach Jacco Verhaeren making it clear he will be watching the 2012 Olympic silver medallist closely due to the surprise coaching switch.
"Even if we don't get the results immediately I really believe they will come because I am really a big believer in what we are doing and the sort of set up I have got," he said.
"The structures around swimming in Australia are so rigid and old school.
"It'd be good for people to see if you can or can't succeed outside one of those programmes."
Following their impressive performances in 2014 the scores are level between Magnussen and fellow Australian Cameron McEvoy, with one gold each from the major international meets.
Magnussen finished first at the Glasgow Commonwealth Games while McEvoy took gold at the Pan Pacific Championships on the Gold Coast.
The four members of Australia's world record breaking 4x100m freestyle relay team from the Commonwealth Games - Cate Campbell, Bronte Campbell, Emma McKeon and Melanie Wright - face off during the trials in a fight for the top two spots in the individual 100m event in Russia.