The son of Cha Bum-Kun, regarded as one of Asia's best players of all time, said the 2-1 defeat by Uruguay was devastating after they controlled much of the game in the second half.
"We were controlling the game, we had played a great second half and then to lose like this... that hurts twice as much," he told Reuters, with tears still welling up in his eyes.
South Korea never gave up after the first early goal from Luis Suarez and piled the pressure on the South Americans with a steady stream of counter-attacks.
Midfielder Lee Chung-Yong finally scored the equaliser on the 68th minute, but it was not enough as Suarez scored the second shortly after.
"They had two world-class attackers, that paid off today. In football you also need some luck. That's what we were missing today," he said.
The fact that this was the first time South Korea qualified to the knockout stage on foreign soil but failed to progress made it a double blow, he said.
"We were so close, it's sad, makes you bitter," the 32-year-old said, trying to control his emotions.
"I'm not the youngest anymore either and who knows if I get to play in another World Cup. That makes it all the sadder."
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