The playmaker has been sidelined with a flu bug, missing the games against Australia and Kuwait.
He was back in action in Friday's win against Uzbekistan, scoring twice in extra-time for the 2-0 win but collapsed after the final whistle and had to be taken from the field on a stretcher.
This is not what coach Uli Stielike needs as he is already without injured duo Lee Chung-yong and midfielder Koo Ja-cheol.
"It's not an excuse, but we are missing two or three big players," said Stielike. "No other team has had to show such mental strength and sacrifice as our boys."
Former Germany star Stielike admits to being taken aback at the pressure his players are under from a football-obsessed nation, who last won the Asian Cup in 1960.
"The pressure the national team is under in Korea has given us some mental problems," he said.
"Now, with these injuries, there's even more pressure on us to reach the final," he added.