China team manager Feng Jianming warned his teenage players of the artificial turf as the defending champions will take on DPR Korea on September 11 in a AFC U-17 Championship quarter-final clash.

After playing all the three group games on the artificial turf in Bishan Stadium, the Chinese players should have got used to the pitch by now. But, as Feng pointed out, this is not the case.

"Our main problem is the artificial turf. It is very unusual for us and now my task is to make my players relax. We shouldn't be stressed out for the match because of this factor." AFC's official website quoted Feng as saying on Sunday.

China, with 24 friendly matches under their belt, came into this tournament as one of the best-prepared teams, yet Feng warned a tough game could be expected against DPR Korea.

"We met DPR Korea in the final of this tournament in Japan in 2004 and won. But they are a very disciplined team and on Monday we will have to do our best. We played a friendly against them in China and won but almost the entire team (DPR Korea) has been changed since then."

Other three quarterfinals will see Japan versus Iran, Saudi Arabia against Syria and Tajikistan playing South Korea.

No team has won the Asian U-17 title twice in a row since the championship was initiated in 1984.