The Commonwealth heptathlon bronze medallist was lying in second place in the IAAF World Challenge Hypo Meeting in Gotzis yesterday when she decided to pull out as a precautionary measure.

"I am gutted because it had been a good first day," Ennis said.

"There are no regrets about coming here but I would not have wanted anything to develop so I decided to withdraw from the second day.

"But I am going to keep positive.

"My ankle is sore and we shall see what the scan shows."

With four of the seven events completed, the City of Sheffield athlete was in second place behind World Indoor bronze medallist Anna Bogdanova (Russia) with 3894 points, just 36 points behind when injury caused her withdrawal.

"I felt soreness in my ankle. It was more a precautionary measure as there are the Olympic Games this summer," Ennis said.

"It could have got worse in the long jump. I will have a scan but I don't think this will affect the plans for the Olympics. It was very sore in the last 50 metres of the 200.

"I am in good shape and am still positive about my preparation for the Olympics."

Her coach Toni Miichiello shared her optimism. "Apart from the injury it was a good day at the office", he said, pointing out that a personal best in the shot was very encouraging.

Nevertheless it is a setback which must be worrying for the Ennis camp as she prepares for this most demanding of events. The 22-year-old is one of Britain's few genuine medal prospects for Beijing.

It is particularly galling considering that she had made such a good start in Gotzis, an event which was billed as an Olympic rehearsal. Her opening event, the 100 hurdles (13.36) had left her just one point behind Bogdanova. The high jump (1.85) also produced more than 1000 points although it was here that she became troubled by the injury, declining her third attempt at 1.88 (her best is 1.95).

The shot, along with the javelin, is the weakest of her seven events and although "only" scoring 762 points, it was a huge success, her 13.52 metre effort beating her previous best.

Finally, a 23.59 200m gave her another haul of more than 1000 points to leave her on 3894, just 48 less that her first day score in last year's World Championship where she finished fourth. Bogdanova lost her lead in the javelin, finally finishing third (6452) behind fellow Russian Tatyana Chernova (6618) and World silver medallist Lydmila Blonska (Ukraine)(6570). The standard shows just how tough it will be to get a medal in Beijing for Ennis and her British team-mate Kelly Sotherton, forced to pull out of the Gotzis meeting after a kidney infection which has disrupted her training.

Richard Buck (York) had his first outdoor race over 400m in an international meeting in Geneva on Saturday.

The Leeds Metropolitan student was runner up in 46.23, a decent mark for his first outing but well down on his British team mate Martyn Rooney who won in 45.19

Jamaica's Usain Bolt ran a world record 9.72 seconds for the 100m in the Reebok Grand Prix meet at the Icahn Stadium in New York on Saturday night.

Bolt, 21, lowered the previous best held by compatriot Asafa Powell, who three times ran 9.74secs. The 6ft 5ins runner was running only his fifth 100m race and was competing in the lane next to America's 100m world champion Tyson Gay.