The Melbourne Tigers star hurt his left knee during the third game of the Test series against New Zealand in Hobart on July 18 and further medical test have revealed the injury is worse than first suspected.

Initially, it was believed Anstey had only a minor strain the medial ligament in his left knee and would only be sidelined for three weeks. But the latest prognosis is up to six weeks off the court which would keep the experienced centre out of the World titles which begin in Japan on August 19.

However, Anstey is still hoping he can make the team if coach Brian Goorjian delays naming the Australian team until the day before the titles start and if the rehabilitation all goes smoothly.

"I haven't been 100 per cent ruled out, but I'm not doing anything for the next camp or the tour of China," Anstey said in the Herald Sun. "I guess it just depends on Goorj."

"The first thing he said was he didn't want me to do anything that would cause a long-term injury. He might wait to see if I can get to China, but if I can't play then I reckon I'd be out of the team."

"Beijing (Olympics) is two years away, but probably the most disappointing thing is you never know if this would be my last major championship," Anstey said.

"It would certainly be my last tournament where I would have a significant role, but it doesn't look like I will now."

The loss of veteran centre continues the Boomers poor preparation. The national team is already without Matt Nielsen plus injured pair Glenn Saville and David Andersen and suffered a humiliating series loss to the New Zealand last week.