Iwan Thomas believes the postponement of the Olympics could aid Team GB's medal tally.
The British 400m record holder expects an extra 12 months will help those who are yet to make a big breakthrough.
The Tokyo Games were put back until July next year after the coronavirus outbreak.
Thomas, who won Olympic silver in the 4x400m relay in 1996, said: "For some it'll be a good thing, I felt for Dina Asher-Smith who is mentally and physically at the top of her game.
"She might still improve but being the current world champion (in the 200m) you are there to be shot at and people fear her a little bit.
"They would have gone in fearing her but one year on you could say she was on the crest of a wave, what a shame she's been paused.
"But for others it's a godsend to have another winter's training behind them. It's the same for everyone, advantage and disadvantage."
Thomas was planning to run the London Marathon for Group B Strep Support after his son Teddy had the life-threatening infection when he was born.
He is now taking part in The 2.6 Challenge after the Marathon was postponed until October after coronavirus hit the sporting calendar.
"The London Marathon raised £66.5million last year and that's money charities rely on," he said.
"This particular charity is so close to my heart, that is what will get me through the marathon when it really starts to hurt. I'll be forever in the NHS's debt for saving Teddy.
"We've had that affection with it ever since Teddy was born and I had someone contact me the other day who has just had a child with Group B Strep and they were in intensive care but came home.
"We were unaware of it so I'm trying my best to raise a bit of awareness."
