Kyle Chalmers needed four cortisone injections for a debilitating back injury before securing his spot at a third Olympic Games.
Chalmers pushed through the pain barrier to win the 100m freestyle at Australia's Olympic selection trials on Thursday in Brisbane.
On a night when Kaylee McKeown again fell just shy of another world record, Chalmers revealed that just 10 days ago he had doubts of swimming at all when his lower back locked up.
"It was a really hard thing to go through so close to trials," he said.
"I have put on a pretty brave face to be able to get through but it has definitely been quite challenging, just getting in and out of bed and starting the day.
"The good thing is that mentally and emotionally, I'm in a very, very good spot so I'm able to rise above the adversity and the challenges that have been thrown at me.
"And that's only because it has happened so many times throughout my career that I've had to rise above something."
Chalmers, the 100m freestyle Olympic champion in 2016 and silver medallist at the Tokyo Games of 2021, won Thursday night's final in 47.45 seconds with William Yang (48.08) second.
Earlier, McKeown insisted she wasn't bothered by coming close to breaking her own 200m backstroke world record.
With 10 metres remaining, she was under record pace but she touched in two minutes 03.30 seconds, outside her benchmark 2:03.14 set in March last year.
"It doesn't bother me at all," McKeown said.
"To be honest with you, I'm just happy to still be swimming around that time, not many people in the world are doing that at the moment.
"There is one that I can think of and she's about to get up and race so I'm nervous to see what she does, but I'm excited for the battle that we have in Paris."
McKeown was referring to American Regan Smith, who will race at the US Olympic trials next weekend.
Smith held the world record for four years before McKeown bettered it in 2023 at the NSW state championships.
McKeown's near-miss follows another on Tuesday night when she snuck within eight-hundredths of a second of her 100m backstroke world record.
McKeown is also reigning Olympic champion in the 100m and 200m backstroke.
On Monday night, she set a Commonwealth record in winning the 200m individual medley, an event she is adding to her program for the Paris Olympics starting on July 26.
In Thursday night's 200m backstroke final, veteran Emily Seebohm (2:10.80) finished fifth and, after having a baby eight months ago, failed in her bid to become the first Australian swimmer selected for five Olympics.
In the men's 200m individual medley, William Petric triumphed in 1:57.54 with McKeown's partner Brendan Smith second in 1:58.12.
Both were outside the automatic qualifying Olympic time set by Swimming Australia with their selection for Paris now resting with selector's discretion.