Lee McConnell will be sweating on her place at next month's World Championships after failing to make the start-line at the Aviva UK Athletics Championships.

The Scot, who is ranked second over 400m in Britain with a season's best 51.52 seconds and won bronze at the recent European Team Championships - withdrew rather than worsen an unknown injury.

Her decision will give selectors a major headache, with world silver medallist Nicola Sanders also missing from Birmingham's Alexander Stadium with an ankle injury.

In the absence of her two chief rivals, world and Olympic champion Christine Ohuruogu eased into Saturday's final in 51.86 seconds.

Originally she had planned to run over 200m but had a change of heart after being outperformed by rival Sanya Richards at last week's Bislett Games in Oslo.

"I need to get some more 400s under my belt and this is a perfect opportunity to do so," said Ohuruogu.

"Things have changed from what I originally planned to do but that is just the way things go.

"I need to start feeling the 400m more in my legs and I am sure I will find out a bit more about what needs to be done after the final. It is all about winning in Berlin."

Meanwhile Clydebank's 110m hurdler Chris Baillie was forced to settle for seventh at the Aviva World Trials and UK Championships, effectively ending his hopes of competing at next month's World Championships in Berlin.

The 2006 Commonwealth Games silver medallist clocked 14.21 seconds, well down on his personal best of 13.44 secs, and notably down on his season's best of 13.90 secs.

Allan Scott was also due to be competing in the 110m hurdles, but was conspicuous by his absence as Andy Turner romped to gold in 13.47 secs.

Meanwhile, Nick Smith just missed out on a place in the 100m final as he crossed the line in 10.70 secs, just 0.15 secs short of the last qualifying spot.