MELBOURNE, Jan 22 (Reuters) - South Korea coach Ulrich Stielike admitted he was on the verge of bringing an exhausted Son Heung-min off the pitch before the midfielder scored twice in extra time to send his country into the Asian Cup semi-finals on Thursday.
The Bayer Leverkusen forward had been laid low by a fever which had restricted him to 40 minutes as a substitute in the 1-0 win over hosts Australia in their final group game on Saturday.
Fortunately for South Korea, Stielike thought better of substituting the 22-year-old, who played the full 120 minutes on Thursday's quarter-final and grabbed the goals that gave his side a 2-0 win over Uzbekistan.
"I was very close to taking him off because he was tired, it was his first game after a long period of sickness," the German told reporters.
"But he stood up and he scored the two goals and it was a good decision not to take him out of the team.
"Both assists were fabulous but you have to be in the right place at the right moment and that's what Son did.
"He can play better, though, and I don't think we have seen the right Son in these four games because of his sickness."
Despite South Korea not having conceded any goals in their four games, Stielike did not hold back in his criticism of his team's technical performance against the spirited Uzbeks.
He was, however, delighted with the mental strength they have shown in Australia.
"I think we can discuss a lot about our technical quality, we missed a lot of passes in the first half, we lost control a lot," he said.
"Where we cannot enter into discussion is about the mentality, the sacrifice of our boys.
"Not many teams have lost two of their best players for the competition as we did in Lee Chung-Yong and Koo Jachul. This explains a little bit our offensive weakness.
"But a lot of teams would lose their mentality if they lost two leaders like that."
Next up for the South Koreans, who are looking to win their third Asian Cup title 55 years after they won their second, is a semi-final against Iran or Iraq in Sydney on Monday.
"I hope they go to extra time tomorrow," Stielike added. "It doesn't matter if it's Iran or Iraq, it's about our own mentality.
"We just have to find a way to come out and play without this big pressure. Just have fun." (Editing by Amlan Chakraborty)