KUALA LUMPUR (AFP) - Japan and Celtic playmaker Shunsuke Nakamura has warned his teammates against complacency as they start the countdown to defending their Asian Cup title.

Japan will be gunning for an unprecedented third Asian Cup crown in the showpiece event in July, but Nakamura knows they must be in top form to avoid any upsets.

"Just like the last two editions, it won’t be easy to win the Asian Cup," Nakamura, who has made a name with his goalscoring exploits in Scotland, told the Asian Football Confederation website.

"Japan will need to spare no efforts if we are to win the title for the third consecutive time."

Nakamura figured prominently in Japan's two previous title runs in 2000 in Lebanon and 2004 in China, and warned that West Asian teams, in particular, were rapidly improving.

Japan are in Group B with Qatar, United Arab Emirates and Vietnam.

"I played under Philippe Troussier in Lebanon on the left side of midfield," he said. "Four years later I had a different impression of the teams as I could see that West Asian teams like Oman had improved vastly.

"In fact, the standards of some of emerging West Asian teams were higher than those of the traditional powerhouses like Korea, Iran, Saudi Arabia and China.

"It was in the last edition that the quality of football really improved."

Nakamura added that Asian players had all the attributes to succeed in Europe, and dismissed suggestions that the generally small size of Asians was an inhibiting factor when playing against the physically superior Europeans.

"Yes, Asian players, especially those from East Asia, are physically smaller (than Europeans) but we can compensate for it with out agility," he said.

"I feel that European clubs are looking at players from Asia and Africa. So if you are good player, you have a chance to play in Europe."