Sun Yang undergoes a training session under the guidance of Zhu Zhigen in early March, after they were briefly reconciled. China Photo Press

"I met the biggest difficulty of my life in the past half year. I was not training well in the last two months, and was not as fit as I was for the Olympics. But I wanted to do my best in the competition and not let down those who supported me," says Sun, who burst into tears after winning the 400m freestyle.

"I have gone through a lot after the Olympic Games, and I have learned how to deal with everything around me in appropriate ways," he says. "All that happened to me were not all bad, but they have made me more mature.

"I am young, and I make mistakes sometimes, but I am back now and I will become better next year," says Sun, adding that he still needs time to reach the lofty heights of Ian Thorpe and Grant Hackett.

After Sun's successive wins, his relationship with his old and new coaches were in the spotlight at the Worlds.

Sun has been coached by Zhang Yadong, the former coach of Luo, since July. Coaching a champion adds luster to a career and also means monetary rewards for winning gold medals for the country.

Zhu extended an olive branch to his student after Sun's domination of the 400m and 800m races.

"My door is always open for him," Zhu says. "I care about him all the time. Let the past be past."

Zhang has made clear that the choice is up to Sun and the sports officials.

Sun has made a point of honoring both coaches.

After winning the 800m freestyle, Sun says Zhang has helped him improve his speed and recognized the coach's strategy in the race. But he didn't forget to express his gratitude to Zhu, who "greatly enhanced my ability with aerobic exercises".

"Both the coaches have brought up champions and have their own strengths," Sun says. He says he's not sure now which coach he wants to pair up with in the long run, "but I hope we can have more space to deal with it, as it is not only a matter for myself but also for Chinese swimming".

"I will consider it carefully and answer the question after the National Games," he says.

Shang Xiutang, deputy head of the swimming administrative center of the State sports authority, expected the public to be more tolerant about the young swimmer, and focus on his athletic result, instead of shortcomings.

Sports commentator Su Dong advises Sun to learn how to cope with the pressure of being the star from his predecessors.

"He is young and good-looking, but he was somewhat losing control after coming into fame since the Olympics.

"It's not easy to be an idol. Even for Yao Ming, Liu Xiang and Li Na, each trifle could be magnified, that's the price of being the focal point," he says. "As long as Sun is on that center stage, he should be careful of everything he does."

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