He's fast but frail – will we now see best of James Dasaolu?

Since his blistering run of 9.91sec in the 100 metres semi-final at the UK Trials, James Dasaolu has become something of an invisible man in sprinting terms. After becoming only the fourth Briton to dip under that dream 10sec barrier, the hope – in fact, expectation – was that Dasaolu would back that up... and soon.

With just 0.04sec to shave off his time to match the British best of Linford Christie, the feeling was that Dasaolu could do so in the final of those trials or alternatively at the Anniversary Games.

But he pulled out of a potential showdown with Dwain Chambers in that final citing cramp then appeared back on form before London, taking a seat alongside the world's fastest man, Usain Bolt, and, while not saying he could beat him, certainly suggested he could give him a run for his money.

It was not to be. The announcement that Dasaolu would be pulling out of the 100m because of a tight hip flexor was met with moans and groans from the expectant crowd and, right now, we have no idea of whether he will be able to test Bolt in the World Championships which begin next weekend.

After pulling out he once again made all the right noises, saying: "Come Moscow, I'll be ready to go. I am running fast this summer because I have made smart decisions with my coach Steve Fudge over the last 18 months and we're not going to change that approach with the World Championships just two weeks away."

Bolt has always told critics in any given season simply to judge him at that year's major championships. At times, he has proved lacklustre only to shine on the biggest stage. His past results mean the global audience can expect just that. But Dasaolu's main issue is his frailty. In his pre-Anniversary Games press conference, he insisted he was not a brittle athlete, but the evidence would suggest otherwise.

In seasons past, he has promised to go fast only for his body to break down at the worst possible moment. It was that which led him to start working with Fudge at the beginning of last year, since when he has improved markedly.

But there are still question marks about how his body will hold up to potentially three rounds of 100m in Moscow. Former British sprinter Darren Campbell has been singing Dasaolu's praises to a certain degree, hinting that his fellow countryman could dip into 9.8sec territory. But Campbell shares the concerns. "To say he is a bit fragile is an understatement," he said before adding: "By not running [in the Anniversary Games], he's put more pressure on himself for the World Championships."

Fudge is adamant he knows what he is doing and has already shown the results to back that up. After all, it was Fudge and the team of medical staff at UK Athletics who got Dasaolu in a position to run 9.91 in the first place.

Fudge is a calm and calculating Scot, previously mentored by Dan Pfaff, who coached Greg Rutherford to long jump gold and is generally regarded as one of the world's leading athletics coaches.

Much attention has been focused on reducing the physical load on Dasaolu's injury-prone body to ensure he peaks at just the right time – namely Moscow – while using those aforementioned UKA medical facilities near where they train in Loughborough.

The other key ingredient has been the work done on the technical aspect of Dasaolu's sprinting and his 9.91 in Birmingham was as near to technically perfect as he could seemingly get.

As the sixth fastest man over 100m in 2013 – the fourth if you exclude the drug-tainted Tyson Gay and Asafa Powell – he is Britain's first genuine sprinting medal contender for some time. But potential is one thing; delivery another. The world will be watching in Moscow.