Memmel, 21, was part of the American women's squad that took silver in team competition at last year's Beijing Olympics, but abandoned her bid to compete at this year's World Championships later this month at the O2.

Ankle surgery late last year after an injury while training at Beijing had hampered Memmel's return to form and she found there was not enough time to regain top condition for the World Championships.

Her withdrawal follows that of Nastia Liukin, the Olympic all-round champion, who asked in August not to be considered by the US selectors because she did not believe that she was ready for such a high-profile competition.

Memmel said: "I have run out of time and I am not quite where I want to be gymnastics-wise.

"I haven't been able to do the number of routines and repetitions that I need. I am going home and will spend the time getting my routines ready for next year."

Memmel, coached by her father Andrew Memmel, was at a final selection camp for the US women's squad where coach Martha Karolyi will decide upon the final London line-up for the event which starts on October 13.

Memmel said: "I thought this would make it easier for Martha and the selection committee in naming the team, because we have so many talented gymnasts who deserve the chance to go to London.

"My dad and I met with Martha and she is very supportive of this decision."


Related stories:
August 2009: Liukin to miss London World Championships