Former Wales tight-head prop Rhys Thomas's heart conditions has improved enough for him to be listed for a life-prolonging transplant.
But the 32-year-old says his health must worsen before a transplant can take place.
He underwent successful surgery to have a special device fitted in September, 2014 in an attempt to ensure a future heart transplant would be possible.
"I've improved and the machine's done its job," said Thomas.
"My pulmonary pressure's come down enough that I was actually put back on to the transplant list two weeks ago.
"[It's a] massive relief for me.
|Rhys Thomas Fact File|
|Born: 31 July 1982 in Johannesburg|
|Wales caps: Seven Debut: v Argentina in Buenos Aires, 2006|
|Clubs/Regions: Newport, Dragons, Scarlets|
|Did you know? Thomas attended King Edward VII School in Johannesburg along with South African rugby players Joe van Niekerk and Bryan Habana|
"I was very nervous… you go into hospital and have a transplant assessment, which takes a couple of days, where you basically go through a range of tests to find out what's been happening since the machine's been in me.
"And it improved enough that I've been put back on to the transplant list.
"It's just a waiting game, really."
Thomas admits he and others in a similar position can only receive a heart transplant at the expense of another person's life.
"It's a pretty bleak outlook, but in order for me to carry on, someone does have to go," he said.
"But while I am sort of healthy at the moment, until I start to deteriorate again I won't actually go on to the urgent list until that point."
He added: "There's not many donors and the ones that do come through tend to go to the people that really need them.
"Basically that's how it is. Until I start showing signs of deterioration or I have infection or something in the line that comes out of my body... that's where we are."
Thomas, who was born in Johannesburg, South Africa, was unconscious for almost two weeks after surgery on 2 September and left hospital four weeks later.
He began his professional career in Wales, making his debut for Newport, the city of his father's birth, in 2003.
He came through the youth ranks at Rodney Parade and made a try-scoring debut for Newport Gwent Dragons following the birth of regional rugby in a 27-5 win over Glasgow in October 2003.
Thomas went on to establish himself as a Dragons regular in the 2004-05 season as the team finished fourth in the Celtic League.
He went on to make his international debut in Wales' 45-27 defeat by Argentina in Buenos Aires in June 2006.
Thomas joined Scarlets from the Dragons in 2009 after making 119 appearances for the Newport-based region.
The prop scored nine tries in 52 Scarlets appearances and scored four times in his 17 games in his final season.
In November 2006, Thomas' career with Newport Gwent Dragons was disrupted by what was subsequently described as a "mystery" chest problem.
That was the start of the heart problems that forced Thomas to retire from rugby six years later.
He retired from rugby in 2012 after collapsing with a heart attack during Scarlets training.
That led to his first open-heart surgery and he retired from the sport later the same year.
Thomas is married with two children and two step-children.