Mark Lewis-Francis is almost certain to miss out on the 2008 Beijing Olympics after suffering an Achilles injury.
The 25-year-old sprinter partially tore his tendon training in Cyprus and now needs an operation to limit the damage. UK Athletics mentor Katharine Merry is concerned the injury could signal the end of Lewis-Francis's career.
"Hopefully we won't lose him to the sport but I do question his mental attitude as well as his physical one," Merry told BBC Radio 5 Live.
"Mark is quite a fragile athlete who wears his heart on his sleeve and he will take this pretty tough."
Merry, Olympic 400m bronze-medallist at Sydney in 2000, continued: "He is one of the athletes I do worry about, in the sense of keeping him involved when he has had a big setback like this.
"I'm sure with commitment, intervention and intensive rehab he will make a successful recovery"
"London 2012 is a big carrot for all British athletes and if he is around the right people then hopefully we can keep him in the sport until then."
Lewis-Francis was understood to have been enjoying training and had found renewed enthusiasm for athletics before suffering the injury.
UKA performance director Dave Collins is also hopeful that the Birmingham-born sprinter can successfully recover.
"On the positive side, it's good that the injury has been caught now before a full tear occurs as this would have been potentially career threatening," Collins said.
"I'm sure with that commitment, successful intervention and an intensive rehab programme he will make a successful recovery. We wish him all the best."
Lewis-Francis achieved the best result of his career at the 2004 Athens Games when he anchored Great Britain's 4x100m relay team to a surprise gold.
But the Achilles injury has put paid to his hopes of repeating that success this summer summer and is the latest twist in Lewis-Francis's difficult career.
Lewis-Francis emerged as a promising junior, winning the world junior title in 2000, but has struggled to build on that potential.
He has yet to win a major outdoor title over 100m and his silverware has come in the relay, where, in addition to his Athens victory, he has collected European 4x100m gold in 2006 and world bronze in 2005 and 2007.
The 25-year-old also revealed at the end of last year that he is just one missed drugs test away from serving a one-year suspension after missing tests in 2005 and 2006.
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In 2005, he was stripped of the silver medal he won in the 60m at the European Indoor Championships after testing positive for cannabis.
Lewis-Francis finished last season sixth in the British 100m rankings and his injury opens the door to British youngsters Craig Pickering, Simeon Williamson and Tyrone Edgar.
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