Japan midfielder Shunsuke Nakamura will break the pain barrier to play in his country's key World Cup qualifier against Australia next month.
The 30-year-old played in Celtic's 2-1 Scottish Cup victory over Dundee at the weekend despite suffering from a groin strain and insisted he would be fit to face the Socceroos on February. 11.
''(Celtic) are fighting for the title so I can't rest,'' Nakamura told Japanese media on Monday. ''It's not too painful.''
Nakamura has struggled with the frequent long-haul trips to play in Japan's World Cup qualifiers and is expected to join the national side late for the Australia clash in Yokohama.
''It would be better to have a week in Japan to prepare but there's nothing I can do about it,'' he said. ''It's exhausting to think about all the games (for Celtic) coming up before that.''
''I'm only human - it's tough,'' added Nakamura, whose contract with Celtic runs out in June. ''I'm trying not to think about it.
''When you reach 30 you often get pain in the knees and ligaments. It's better to go there with a positive attitude. It takes up a lot of energy but I want to play.''
Nakamura, who has had various knee and ankle injuries over the past two seasons, has been linked with a return to Japanese side Yokohama F-Marinos.
Australia lead Group One in the final round of Asian World Cup qualifiers with a perfect nine points from three games, two points ahead of second-placed Japan.
The top two from each of the two five-team groups will qualify automatically from Asia for the 2010 World Cup finals in South Africa.