Son joined South Korea only after the national team had played two group matches. It was part of an agreement between Son's Tottenham Hotspur and South Korea, whereby the Spurs made Son available for the Asian Games last summer in exchange for holding him back for the early portion of this tournament.

    South Korea managed just one goal apiece against the Philippines and then Kyrgyzstan. And Son, the national team captain, was expected to provide an immediate boost, and the versatile attacker, a contender for the Premier League's Player of the Month for December, made some positive impact in South Korea's 2-0 win over China. But in the ensuing two matches, a 2-1 win over Bahrain on Tuesday in the round of 16 and then Friday's loss to Qatar, Son was well off his game.

    But Son, who arrived in the United Arab Emirates on Jan. 14 and played the full 90 minutes against China two days later, hit a wall. He had already played a heavy schedule with the Spurs, and  all that action and traveling had taken a toll on the 26-year-old.     

    "I'd rather not talk about this, but (in the buildup to the tournament), I rarely felt great physically," he said. "I was losing sleep. I should have taken better care of myself."

    South Korea had five days off between their final group match and the first knockout game. In the round of 16, South Korea got dragged into extra time against underdogs Bahrain, and Son played  the entire 120 minutes.

    And three days later, it was more full-time action for Son, who ended the tournament without a goal.

    "I thought I would start to feel better (after the China match), but it didn't happen," Son said. "I know a lot of people expected big things out of our team. I was so mad at myself for not being able to play well. I think we ended up getting this result because of my play."

    Son said South Korean players should look at themselves in the mirror after the earlier-than-expected exit from the tournament.

    "I think the future of the national team will change depending on how we deal with this result," he said. "We have to keep in mind that there are no teams in Asia that we can take lightly, and we'll have to try to keep improving ourselves." (Yonhap)