Japan playmaker Shinji Kagawa suffered a heart-stopping moment during training at the Asian Cup on Saturday when he came down awkwardly on his elbow while playing foot volleyball.

Despite the scare, the Borussia Dortmund midfielder insisted he was not seriously hurt as the defending champions prepare for their opening Group D game against Palestine on Monday.

"It was a bit of a close shave but it's fine," Kagawa told Japanese media after sustaining bruising and sitting out the rest of training as a precaution.

"I just landed heavily on my elbow, nothing too serious. It would have been embarrassing to injure myself doing that."

Kagawa will have added incentive to do well at the Asian Cup in Australia after fracturing a metatarsal in the semifinals of the 2011 tournament and missing Japan's victory over the Socceroos in the final in Doha.

"It was a frustrating situation for me four years ago and I want to be able to contribute this time," said the former Manchester United player, who failed to make an impact at last year's World Cup where the Blue Samurai flopped badly.

"People expect that of me and if I can play well and we get results it will give me confidence, which is what I need. But the main thing is that the team does well."

Japan, who have lifted the Asian Cup a record four times, are also drawn alongside Jordan and surprise 2007 winners Iraq.

However, hosts Australia threw down the gauntlet with a thumping 4-1 win over Kuwait in the tournament opener on Friday.

"I saw a little bit of the match and it certainly whetted my appetite," said Kagawa. "As for Palestine, we haven't seen much videotape of them so it's hard to make any judgements. We just have to stay focused on the task ahead."