China international Zheng Zhi has a back injury and is a major doubt for next month's Olympic Football Tournament.

The Charlton midfielder was carrying the injury throughout the latter stages of China's unsuccessful world cup qualification run and is struggling in his bid to represent the host nation in Shenyang, one of five cities hosting the tournament.

China's Olympic team coach Ratomir Dujkovic believes Zheng's absence would be "a severe loss for China".

"Zheng Zhi is China's best player," Dujkovic said. "If he can't play for the Olympic side, it will be a severe loss for China."

The Serb added: "If he were not in form, it would be pointless for me to include him in the Olympic squad.

"I hope he could recover and I won't make a decision to drop him until the last minute."

Dujkovic said he has been preparing to be without Zheng in August and believed youngster Chen Tao can step up as the successor.

"Chen Tao has showed strong desire to play in the Beijing Olympics," he said. "It is a very good sign."

Djukovic has short-listed keeper Song Zhenyu, defender Li Weifeng, midfielder Liu Jian and forward Han Peng alongside Zheng as the potential over-aged players for the Olympic team.

China, who will be taking part in only their second Games, were drawn in Group C alongside Belgium, debutants New Zealand and five-time world champions Brazil, who last claimed a medal at the Olympics in Atlanta in 1996 and have never won gold.