London 2012: Sarah Stevenson insists she will be fighting fit for Olympics after knee injury

Injured world champion Sarah Stevenson insists she will be fit to fight for Olympic gold at London 2012.

Stevenson had cruciate ligament surgery this week after she was injured during a recent training camp in Mexico.

She has spoken of her desire to win Olympic gold as a fitting tribute to her parents who both died last year.

"I'll be at London 2012. I'm not worried, I'm more determined. I've been through too much to let a knee injury get me down," the 28-year-old tweeted.

Stevenson's mother, Diana, was diagnosed with cancer in January and passed away in October, just three months after her father, Roy, died following a brain tumour.

The Doncaster fighter has until the end of May, when Great Britain selectors will pick their four-strong squad, to prove her fitness.

She has been ruled out of the upcoming Dutch and German Opens and is likely to miss the European Championships in Manchester which start on 3 May.

But she remains optimistic of competing in London 2012 and attempting to improve on the bronze medal she won at Beijing 2008.

Great Britain performance director Gary Hall added: "If anyone can return from this then Sarah can.

"She is a consummate professional and will be doing everything in her power to show the selectors she is the girl for the job."

Stevenson won her third Taekwondo World Championships title by beating China's Guo Yunfei in the -67kg category in Gyeongju, South Korea, last year.