Christine Ohuruogu’s prospects of defending her World Championship crown next month were rated at only 50-50 on Friday night after the extent of her hamstring problem was revealed.

Great Britain’s solitary Olympic gold medal-winner on the track last year will miss the Aviva London Grand Prix at Crystal Palace next week as she focuses on her fight to be fit for Berlin. “It’s about the bigger picture,” Lloyd Cowan, her coach and architect of her success, said.

The bigger picture is a gloomy landscape from the blue period for Charles van Commenee, the head coach of UK Athletics. Even if Ohuruogu travels to Germany, it is hard to see her being in the best shape to take on Sanya Richards, the American quarter-miling queen, who is ravenous for revenge after being beaten in the Olympic 400 metres final.

Ohuruogu withdrew from Friday night’s expected showdown with Richards at the Golden League meeting in Paris and will concentrate on getting over the slight tendon tear at the top of her right thigh. She saw a specialist on Thursday and it emerged that she may have had the problem for some time.

Ricky Simms, her agent, said that she would be fine to open her defence in the heats at the World Championships on August 15, but Cowan said that she had only a “50-50” chance. Ohuruogu will need to be in peak health and form to beat Richards again, although the American confirmed that she has health worries of her own.

Richards, who set a record in Paris by clocking her 37th sub-50sec run, compared with Ohuruogo’s two, revealed that she still suffers from Behçet’s Syndrome, which affects the immune system and is brought on by stress.

“I don’t think my Behçet’s will be in the past for a long time,” the Olympic bronze medal-winner said before running in Paris. “I had a flare-up in April and it took me some time to get over that one. I just hope I can see out the season without any more. It’s brought on by stress and that’s hard to keep away from. We’ve been working with it for two years so we’re a bit smarter now, but it’s definitely a worry. That’s why I want to get home and get with my doctors.”

Richards said that she would have been surprised had Ohuruogu run in Paris, but there was no kidology involved in the Londoner’s withdrawal. Her team opted for the safe option after visiting a specialist. She will not race again before the World Championships, which means that, if she makes the start line, she will do so knowing that 20 women have run faster than her this season.

Ohuruogu is not the world and Olympic champion for nothing, however, and has a mental strength and habit of peaking that may upset the odds given by Cowan. Van Commenee will hope that she does because his first significant championships as head coach are in danger of being jeopardised by injury. Mara Yamauchi, second in the Flora London Marathon this year, and Tasha Danvers, third in the Olympic 400 metres hurdles final last summer, have pulled out of the event in Berlin. Paula Radcliffe has not raced since winning the New York Marathon last November and is on the comeback trail after having surgery to remove a bunion.

Other potential medal hopes, such as Kelly Sotherton, Martyn Rooney, Goldie Sayers and Lisa Dobriskey, are striving to put injuries behind them. Nicola Sanders, runner-up to Ohuruogu at the last World Championships, has become the forgotten woman of British athletics and has barely run this summer.

Even if Ohuruogu does make it, Richards let it be known that she will not be such a tactically naive opponent this time. Richards went off like a train in Beijing but ended up folding like an Olympic origami expert, leaving seasoned watchers such as Michael Johnson to observe that “she just can’t get it done” at leading championships.

“He’s just stating facts and there’s nothing I can say about that,” Richards said. “I’m only 24 and have a bright future. I’m consistently under 50 seconds and maybe I can do that 50 times. To me that’s as huge as winning a whole bunch of titles. I respect the fact Christine is world and Olympic champion but I know my time will come.”

There are two shreds of comfort for Ohuruogu as she battles against the taunt of time. The first is that Richards appears to be feeling the pressure and said that she has not decided whether to distance herself from the United States team in Germany in an attempt to make it feel like a normal Golden League meeting. The second is that Ohuruogu went to the last World Championships in Osaka, Japan, having run only one 400 metres race all year, a tardy 53.09sec in Scotland, but went on to win.