Optimism may be golden but reality may not glitter so brightly. With London calling athletes from all over the world, hopes of a medal haul for China to match the golden times of four years ago may be premature. 

Sports Minister Liu Peng put expectations into context as he announced the Olympic delegation in Beijing on Tuesday. 

The delegation consists of 621 officials, athletes and coaches. Competing for medals will be 171 men and 225 women. 

The average age of the squad is 24.68 years and 244 of them have no previous Olympic experience. 

"In every sport, whether you are strong or not, you have to be prepared to face unprecedented challenges," Liu said. 

Four years ago in Beijing, China topped the medal table with 51 golds. 

It will be more difficult this time without home advantage and many of the tops stars have retired or are injured. 

"Four years ago, we achieved remarkable accomplishments. In London, China will be under the spotlight to see if we can repeat the feat," Liu said. 

"But the reality is tough. In the past four years, other countries and regions have prioritized Olympic preparations. We have to be fully prepared for all the difficulties and challenges." 

Big names and gold medalists such as Zhang Yining, Zhang Ning, Guo Jingjing, Yang Wei and Cheng Fei, from the traditionally strong events, like table tennis, badminton, diving and gymnastics, are absent. 

The younger generation, and coaches, will have to bear the burden of expectation. 

Badminton head coach Li Yongbo is one of those shouldering the burden even though defending champion Lin Dan is still in his prime. 

"The greater the expectation, the more pressure we feel. If people played down their expectations, the athletes might perform better," Li, whose team won three of the five golds on offer in Beijing, said. 

There are only 16 days to go before the opening ceremony and some teams have already arrived in London to test venues. 

Liu said this is a significant period for athletes as they hone their bodies. 

"This is a key period. The teams must tune up mentally and physically. It's also important to balance the training with plenty of rest and avoid injury." 

Liu also pointed out that winning is not everything and stressed the importance of using the Olympic platform to show the true spirit of sport. 

Although China did well in the Beijing Games, top sports officials insist that China is still on its way to becoming a powerhouse like the US and Russia. 

Of the 26 sports in London, China will not participate in soccer, equestrian and handball. 

In the more popular and major events, like athletics and swimming, China only has a few competitive stars. 

"Hopefully, we can make some progress in London in those events where we lag behind," Liu said. 

"We are still on the way (to becoming a sports powerhouse). We took a giant step forward in Beijing. The London Games is another chance to progress as it will inspire more Chinese people to take up sport in their daily routine." 

Liu also pointed out the importance of the fight against drugs. 

"I want the delegation to have a clean Olympic Games," Liu said. "We made great efforts and did a good job in the past 10 years. We cannot slow down." 

chenxiangfeng@chinadaily.com.cn