Exclusive by Mark Mitchener
Iwan Thomas has decided to pull out of the Commonwealth Games, where he was due to run for Wales in both the individual 400m and 4x400m events.
He told BBC Sport: "It’s been one of the toughest decisions of my career.
"But for the last six or seven years, I’ve run half-fit or been injured, and I’ve really under-achieved.
“I’ve been in fantastic shape, but two weeks ago I picked up a hamstring injury - and I’m fed up with putting myself on the line when I’m not 100%.”
Thomas, 32, still holds the British record for the 400m, clocking 44.36 seconds in Birmingham in 1997.
The Welshman then won both the Commonwealth and European 400m titles in 1998 - and was awarded the MBE the following year - but he has been hampered by injury problems since then.
He was unable to defend either title in 2002, although he ran in the Wales relay team at the Commonwealth Games in Manchester, and in the Great Britain 4x400m quartet at the Sydney Olympics in 2000.
And the decision to miss Melbourne has come as a bitter blow after a successful winter of training.
“I’ve trained so hard this year, but I feel if I go out there not feeling 100%, I won’t run as quickly as I could have done,” he said.
"It is tough because it’s fantastic to run for Wales and it’ll be my last ever Commonwealth Games. I’d love to go out there and help the team, but I don’t feel I’d do myself justice.
"The decision would have been easier if I hadn’t been running so well this winter, as I could have said to myself ‘You’re not in the best of shape but go to Melbourne, enjoy it, run as well as you can and help Wales in the 4x400m’.
"But the honest truth is that I have been in fantastic shape - I really kept my head down this year because I wanted to go to the Commonwealth Games and show a lot of people what shape I was in.
"So because I’ve picked up a slight niggle, I don’t really want to go out and, let’s say, run 45.5, as I know I can run better than that and I have been training better than that.
“So I’d rather wait for the AAAs or the European Championships later this summer, and only come out and put myself on the line when I can do myself proud.”
Having spent three years based in Loughborough, Thomas returned to Southampton in 2005 to work with coach Mike Smith.
Smith had previously coached the Welshman for an eight-year spell, including his golden summer of 1998.
“Myself and Mike have worked so hard this year, and to be perfectly honest, Mike would rather that I went out there,” Thomas revealed.
"He was of the opinion that ‘You could still go there and run quickly, get some sun on your back, your hamstring will be fine and you might surprise yourself’.
"But he respects me - and I explained that it’s my name, I’m the person I’ve got to live with if I don’t run well. I’d rather wait until I can do justice to myself.
“I hope people can respect my choice for not going - I just want to be the best I can be again.”