Ian Thorpe's hopes of competing at a third Olympic Games are on the line this week at Australia's national swimming trials in Adelaide, where a number of local rivals are aiming to crush the five-times gold medallist's London dreams.
The 29-year-old, who announced his comeback just over a year ago after more than five years out of the pool, has all but written off his chances of breaking into Australia's fiercely competitive team, admitting that he left his run too late to be fully fit for the trials.
"It's been bloody frustrating that I've trained the house down. I thought it would translate into good racing and results," Thorpe said in a column carried by local newspapers over the weekend.
"It hasn't happened and that has tested my mental strength and my patience. I truly believe my hard work deserved better. I'm hoping my racing mojo returns for Adelaide."
Australia's head coach Leigh Nugent believes Thorpe could still spring a surprise at the South Australian Aquatic and Leisure Centre, where he will focus on the 100 and 200 metres freestyle events.
"I think with someone like Ian, the history he's got and knowing his competitive capabilities, you could never write him out of the equation," Nugent told local media.
"I've been around a long time and I've had a lot to do with Ian and with swimming at this level for almost two-and-a-half decades and with him, you've got to expect for him to pull something out of the bag ... He just has that sort of ability."
The 11-times world champion's form has dismayed an adoring public that remembers him as a podium-topping titan, but fingers remain crossed he will pull an ace from his sleeve to book his ticket to London.
Either way, Thorpe, who makes his first appearance in the 200 preliminaries on Friday, has his work cut out to finish fastest or runner-up in the finals, which would guarantee an individual berth at London if he meets qualifying times.
His best hope appears a top-six finish, however, which would at least offer a chance of selection in the relays.
Thorpe's stiffest competition in the 100 freestyle will come from 20-year-old title-holder James Magnussen, who swam a stunning 47.63 to win gold at the world championships in Shanghai last year.
Australia's first world champion in the blue riband event, Magnussen, dubbed "the Missile" by local media, has talked of stripping Brazilian Cesar Cielo's world mark of 46.91, set in a now-banned swimsuit at the 2009 Rome world championships.
Thorpe has a better chance to qualify for the 200, although his best time of one minute, 50.79 seconds since returning to competitive swimming in November sits a lowly 19th in national standings this year.
Another swimmer striving to reach her best against the odds is triple Olympic champion Stephanie Rice, who will defend her women's individual medley titles against a strong field.
Rice, who took gold in the both the 200 and 400 medley at the Beijing Olympics, has been dogged by injury in the intervening four years and carries a nagging shoulder problem into the event.
The 23-year-old had arthroscopic surgery in November and is less than halfway through a six-month rehabilitation period but is determined to swim through the pain to secure a spot on the plane to London.
Rice will be joined in Adelaide by fellow Olympic champions Libby Trickett and Leisel Jones, who along with ageing former freestyle world champion Michael Klim and Geoff Huegill, have come out of retirement for a last-ditch Olympic bid.
The 27-year-old Trickett, who retired in 2009 after winning 100 butterfly gold and the freestyle silver at Beijing, will battle favourite and world silver medallist Alicia Coutts in the butterfly event.
Jones swapped the pool for beauty school in a year-long sabbatical in 2009, and relinquished her status as the world's best breastroker to Rebecca Soni.
The 26-year-old came back in 2010 and then finished second behind Soni in the 100 breaststroke in Shanghai but should qualify to challenge the American again in London.
Klim, who won a pair of relay golds at the 2000 Sydney Olympics, retired in 2007 with a debilitating shoulder injury but was inspired to return to the pool last year after Thorpe announced his comeback.
He will compete in the 100 butterfly against his 33-year-old one-time arch-rival Huegill, who won bronze in the 50 event at Shanghai to cap an extraordinary comeback after beating depression and weight problems.