As if playing three time world champions Germany was not hard enough, the United States face the added disadvantage of a hostile crowd in their World Cup quarter-finals clash in Ulsan on Friday.
Although only a few hundred German supporters are expected at the game, tens of thousands of South Koreans are likely to vent their latent resentment of the world's only superpower by backing the Europeans.
"I will definitely cheer for Germany," said Chung Hyun-hwa, 28, a sales manager from Ulsan who will be in the crowd in the 44,466-seater World Cup stadium on Friday.
"Firstly, I think Germany are one of the greatest teams in the world, but I think it is also natural for Korean people not to support the United States," she said. "There is still some bad feeling between us."
That will be nothing new for the Americans who have been booed on the pitch in most of their games in South Korea, which is home to 37,000 U.S. troops.
So far, it has had little effect on their game. After all, they were the only team to take a goal off the South Koreans in group D, holding the co-hosts to a 1-1 draw in front of sea of red-clad local fans.
U.S. players have brushed aside the South Koreans' antipathy but the few hundred American fans who shout themselves hoarse at every match have expressed frustration at the constant barrage of boos which they see as undeserved and unsporting.
It was only natural for locals not to support the United States in the first round when South Korea were vying with them for qualification for the last 16, they say.
But the hostility endured during the Americans' second round clash with Mexico, when thousands of South Koreans, some wearing Mexican strips and face paints, backed the South Americans.
For college student Ahn Sung-hun, 24, opposing the United States is a matter of principle.
"I'm concerned that America is a country that only thinks about its own well-being," said Ahn, who hopes to attend Friday's match to cheer on the Germans.
"Korea has been hurt a lot by the United States, financially, in sports events and in other ways."
High on his list of bones to pick is South Korean speedskater Kim Dong-sung's disqualification in the 2002 Winter Olympics in Salt Lake City and the award of the gold medal instead to U.S. skater Apolo Anton Ohno.
South Korea's Ahn Jung-hwan recalled the incident when he celebrated his goal against the Americans in the first round with a mock speedskating routine.
"When I saw Ahn do his skating imitation I felt so happy," said the student.
Businessman Jung Youn-il said South Korean resentment over that incident and the U.S. military presence was exaggerated.
"That kind of feeling has diminished now," said Jung, 38, who already has his ticket for the U.S.-Germany game. "I used to feel like that but not any more."
But he too will back Germany, hoping South Korea can enjoy the honour of meeting them later in the competition.
"I'm not against America, I just hope the Korean national team can play against Germany because they are one of the best teams," he said. "I really hope Germany can reach the semi-finals."