Jelena Dokic has played down the injury of her ankle

JELENA Dokic cancelled a scheduled practice session as her Australian Open fairytale took a mysterious twist.

Dokic is receiving treatment for a sprained lateral ligament in her left ankle before her quarter-final blockbuster against Russian Dinara Safina.

Though Dokic appears certain to play, she is likely to require heavy strapping - and possibly a mild pain-killing injection - to continue her inspirational run.

Dokic had been pencilled in for a 5pm training session at Melbourne Park, but did not front. There was also no sign of the Dokic camp at the Open's other training venue at Albert Reserve.

"Jelena got physiotherapy treatment on her ankle last night and today. The treatment is progressing well. It was always intended that she would not practise today and use this as a recovery day," coach Borna Bikic said.

But former player Marty Mulligan, a key member of the Dokic camp, assured fans the darling of the tournament would be fit.

"I spoke with Jelena this morning, she said her leg was OK so that's fine," Mulligan said.

Sports doctor Peter Larkins said Dokic was fortunate to escape more serious damage and questioned why she did not have both ankles strapped.

Larkins said a "loose" joint appeared to avert a heartbreaking exit after Dokic rolled the ankle late in the dramatic battle with Russian Alisa Kleybanova on Sunday night.

"My reaction was she was probably a loose-jointed person who could get away with rolling the ankle and not get a lot of bleeding or swelling," Larkins said.

"My first impression was she was in trouble, but it didn't swell up in the first five minutes, which was a good sign.

"It will be a lot sorer today than it was yesterday."

Mulligan, the Fila director of tennis sponsorships, sits in Dokic's players' box and has been aligned with the rejuvenated star for almost 10 years.

"She can play a good match tomorrow - she will have the whole crowd behind her," Mulligan said.

Open officials played down the non-appearance of Dokic, saying the time was held well in advance, pending confirmation.

Officials revealed defending men's champion Novak Djokovic had made a similar change of plans after winning a marathon match after Dokic's victory.

After the match, Dokic said her ankle had been sprained.

"My foot really got stuck," she said.

Larkins, who has diagnosed scores of injuries in the AFL, said heavy strapping would be used and indicated a pain-killing injection would work.

"Without wanting to encourage kids on this, it is a ligament injury. A jab would take away the pain in the ligament," Larkins said.

"It would be OK providing the ligament is working. I reckon she won't need it though with some ice and physio."

Larkins said he was surprised more tennis players didn't strap up both ankles as a preventative measure.

"At that level of professionalism, in a sport that is notorious for ankles, it is a bit of a surprise," Larkins said.

"You don't see Lleyton Hewitt go out without strapping."

Cameras yesterday showed Serena Williams wearing heavy strapping on her ankles.

Meanwhile, Dokic's stunning performance has prompted unprecedented interest around the country that's set to continue tonight.

Dokic has been a ratings winner for Channel 7 and she's become the night-time queen on Rod Laver Arena because of her pulling power with TV audiences.

Seven has been keen to push the scheduling of Dokic at night on the showcase court to maximise prime-time ratings.

A national audience nearing three million viewers is tipped for tonight's match with no cricket being televised on rival network Channel 9.

Dokic's first four matches of the Open have generated peak audiences of about two million viewers.

Her fourth-round clash against Kleybanova attracted 2.3 million viewers.