Celtic midfielder Shunsuke Nakamura, a key player in Japan's qualifying campaign for the 2010 FIFA World Cup South Africa™, is a fitness doubt for an away match against Thailand on Saturday.

Nakamura, whose left-foot kicks helped Celtic to their third straight Scottish Premier League title, was feeling recurring pain from an old injury to his right ankle, according to Japanese press reports. He jogged and had a light workout without his boots at Japan's training camp in Bangkok on Tuesday with the painful ankle taped.

"The pain usually goes away in a couple of days. But the ankle still hurts even if it's taped," Nakamura, who turns 30 later this month, told Japanese reporters. "I'll try to be alright for the Thailand match."

Japan coach Takeshi Okada said of Nakamura: "He didn't want to strain himself as the pain had not subsided. I must think about the worst case in which it is impossible for him to play."

The pain came back after a 1-1 away draw with Oman on Saturday, which put Japan closer to a berth in the final Asian qualifying round with seven points, three points behind Asian Group 2 leaders Bahrain and three clear of Oman. Thailand stand with a single point with two games to play after a 1-1 draw with Bahrain at home.

Okada said left back Yuto Nagatomo, who had missed the Oman match due to pain in his right ankle, might also sit out the weekend game.

Japan's firepower will be depleted against Thailand due to the absence of Vissel Kobe striker Yoshito Okubo, a former Mallorca player, who had been red-carded for kicking Oman goalkeeper Ali Al Habsi in Muscat.