Germany-based midfielder Koo Ja-Cheol will miss Korea Republic's 2014 FIFA World Cup qualifier against Uzbekistan next week because of an injured ankle, officials say.
The Korea Football Association said on Wednesday the Augsburg player, 23, was not included in the squad that left for Tashkent the previous day.
Korea Republic, top of Asian qualifying Group A after beating Qatar 4-1 and Lebanon 3-0, takes on Uzbekistan next Tuesday afternoon (local time). Uzbekistan has only one point from two games.
Koo's agent said he had sustained an injury to his right ankle in a league game against Schalke last weekend.
Koo, who captained Korea Republic's Olympic team to a bronze medal in London, moved to Augsburg on loan from Wolfsburg earlier this year.
"I feel sorry for his absence but I'm not worried so much because there are many other players who can replace him," national coach Choi Kang-Hee told reporters on Tuesday.
"It seems to be impossible for Koo to play for my squad this year."
Koo was one of eight Olympic players selected by Choi for the full national squad.
Midfielder Nick Carle will return to Sydney FC after a 12-month loan deal with Bani Yas in the United Arab Emirates Pro League.