Tennis: Dokic ready for biggest Open test

She might have one dodgy ankle, but Jelena Dokic will have 20 million hearts to prop her up as her quest for the biggest grand slam miracle continues at the Australian Open on Tuesday night.

Dokic's captivating return to top-level tennis and back into the good books of the nation she quit faces its toughest test against world No.3 Dinara Safina in the quarter-finals.

The 25-year-old will also have to battle fatigue from four, three-set matches at the tournament ahead of this one, as well as any lingering pain from rolling her ankle late in Sunday's brave fourth-round win over Russian Alisa Kleybanova.

Dokic's coach Borna Bikic said on Monday the injury had responded well to treatment and the reborn Australian herself shrugged off any suggestion the mishap was tournament-threatening.

"Jelena got physiotherapy treatment on her ankle ... the treatment is progressing well," Bikic said.

"It was always intended that she would not practice today (Monday) and use this as a recovery day."

Dokic's fairytale run so far has guaranteed her at least a top 100 world ranking after the tournament.

If she beats Safina, Dokic's ranking is likely to move into the mid-sixties.

But, as she prepared for her first appearance in a grand slam last eight since the French Open in 2002, the former world No.4 refused to put any pressure on herself.

"Whatever happens doesn't really matter. I'm not thinking about a semi-final, but just putting in a good match," Dokic said.

"I'm playing a girl that's two, three in the world, could be No.1 after this tournament and is probably the favourite for the tournament at the moment with everybody going out.

"This is a really pure match with no pressure on me. Even if I lose easily, it will not be a surprise (but) I would like to see how I can do against her."

Victory would put Dokic into a semi-final on Thursday against either Russian seventh seed Vera Zvonareva or French 16th seed Marion Bartoli and keep alive her dream of becoming the lowest-ranked grand slam champion ever.

In other quarter-finals on Tuesday, men's second seed Roger Federer continues his bid for a fourth Australian title when he plays rising Argentine star Juan Martin del Potro while defending champion Novak Djokovic meets Andy Roddick.