Zhou Jihong, team manager of the Chinese national diving team, said on Friday that her star-studded squad will face great difficulties in winning all the gold medals at the Shanghai world championships in July.

Zhou, China's first diving Olympic champion at the 1984 Los Angeles Olympics, said, "I don't mean that we are unlikely to achieve that goal. I just want to say that it's very difficult. But we will try our best to make good preparation for each discipline."

She said that Chinese divers will face tough challenges in men's events. "Our rivals are improving fast especially in men's events. We will have no reason to belittle any competitors in Shanghai."

China will not have a super star in the squad at Shanghai after four-time Olympic chamion Guo Jijing retired early this year. Guo won the women's three-meter springboard and synchronized springboard at five straight world championships from 2001 to 2009.

Zhou said it will take time to have someone else to replace Guo in her team. "It's impossible for a new star to emerge soon after Guo retired. We must wait but our team will work hard to have a new super star."

China won seven out of eight gold medals at the Beijing Olympic Games and took seven out of 10 in the 2009 Rome world championships.