Birchfield Harriers' Kelly Sotherton received a boost to her hopes of Olympic gold in the heptathlon this year when reigning champion Carolina Kluft announced she would not defend her title in Beijing.
But Sotherton said she was sorry the Swede was not taking part in China as it took away her final chance to try and beat her.
The 25-year-old champion, who has lifted every major multi-events title since winning the World Championship gold medal in 2003, has intimated for several months that she lacked the motivation to carry on her multi-event career and was looking at other options. She now plans to compete in the long jump and triple jump.
Beating Kluft at a major event has long been a key motivating factor for Kelly Sotherton, who trails 9-0 in their head-to-heads.
Despite that overwhelming record, Sotherton believes she is under more pressure to win the gold in Kluft's absence.
Sotherton said: "I am disappointed Carolina is not going to be competing. Although it leaves the competition wide open, it takes away my chance of finally beating her.
"I understand it adds to the pressure on me, but my aim was to go out and win gold anyway, so my goals and preparations won’t be changing in any way.
"Carolina’s a sensational champion and I believe there will be a chance for us to meet again in the future."
Sotherton took bronze at the Athens Olympics in 2004, behind Kluft and Austra Skujyte. She also finished third as Kluft took gold again at the World Athletics championships in Japan last year.
At the European Indoor Championships, in Birmingham last year, Kluft narrowly pipped Sotherton to gold in the pentathlon.
However, at this month's World Indoor Championships in Valencia, after Kluft pulled out with injury, Sotherton again failed to land gold in the pentathlon, beaten to first place by Belgian Tia Hellebaut.
Swedish Athletics Federation spokesman Fredrik Trahn said: "Carolina hasn't said she has quit the heptathlon for good and may return at some time in the future.
"She has no competitions lined up in the foreseeable future. Now she will concentrate on the long jump and triple jumps."
Trahn added: "She has lost 100% focus and spirit for the event, but I am sure she will return to it when getting her motivation back."