These are worrying times for Asia's most successful World Cup team. South Korean fans are proud of seven consecutive appearances at the World Cup but after a third consecutive defeat against an international rival, there is a growing feeling that another trip next year to football's marquee tournament is far from a foregone conclusion.
A crushing 4-0 loss to Croatia in a friendly at London on Wednesday, South Korea's biggest defeat since 2001, would not be a major source of stress had the national team not also lost to Australia in November and Iran in October in performances that were also disappointing.
Currently, the 2002 World Cup semifinalist occupies second spot in its continental qualifying group for Brazil 2014. South Korea is a point behind leader Uzbekistan in Group A, level with Iran and Lebanon. For the 2006 and 2010 editions, the South Koreans qualified with games to spare.
It's going to be a more difficult journey this time, but officials are trying to allay domestic concerns about the recent slide.
"We still have three of our last four qualification games at home," Korea Football Association head of development Park Yong-soo told The Associated Press. "We are confident that we can get the points we need to go to Brazil in 2014. After the Croatia game, there is work to do and that starts against Qatar."
Next month's home World Cup qualifier against Qatar has become a must-win game for the team which started the final round of qualification with a convincing 4-1 win at Doha, followed by a 3-0 victory at home to Lebanon. The turning point of the campaign came at Uzbekistan in September when poor defending turned what had looked to be a victory into a 2-2 draw.
An October loss in Iran against a team playing with 10 men confirmed that qualification was going to be a close-run thing. That poor result has developed into a bad run with subsequent friendly defeats to Australia and now Croatia.
"It was a clear defeat . but I am not going to over-react after just one game," South Korea coach Choi Kang-hee said after the most recent loss. "We will build on our experience from today's match and earlier games to try and develop more cohesion. Our upcoming opponents will play more defensive games than Croatia and we have to find our offensive combination."
Choi has been searching for the right combination in attack with mixed success. Sunderland striker Ji Dong-won and Son Heung-min, one of the stars of this season's Bundesliga with Hamburg, failed to break through the Croatian defense, and the second-half introduction of Park Chu-young, formerly of Arsenal, and Lee Dong-gook has failed to click.
"The coach repeatedly told us to attack quickly and at a high tempo, and at the start of the game we did just that," said Son, who has scored seven goals in the Bundesliga this season, "but gradually we stopped doing so. It was a disappointing result."
While the attack was relatively toothless in London, the defense was again a major cause for concern. For the fourth consecutive game, South Korea conceded a goal from a set piece, a problem that has been described by the local media as a "set piece black hole."
"It is something that we have to keep working on in order to get right and we will do that," Choi conceded. "This is an important problem with four games left in qualification."
Choi was a successful coach with Jeonbuk Motors from 2005 to 2011 and led the K League team to two domestic and one Asian championship. A former international player, he reluctantly took the national coaching job in December 2011 after Cho Kwang-rae was fired following a loss in Lebanon.
Choi's insistence that he will return to Jeonbuk in June at the end of qualification regardless of whether Korea is successful in its quest to reach Brazil has created uncertainty on and off the playing field.
The reaction from fans after the Croatia loss was one of dismay with thousands of disgruntled comments left on the country's major internet portal sites.
Park Sung-hee was among them, writing: "We have players in the English Premier League, La Liga and the Bundesliga but the standard of the play was worse than a mid-table K League team. If we play like this perhaps not qualifying for the World Cup will be a blessing."