South Korean forward Son Heung-min has apologized for his towel-tossing conduct in a recently friendly match against Spain, saying he was mad about his performance in the team's 6-1 defeat.

Son threw a towel at the bench after he was subbed out during the loss at Red Bull Arena in Salzburg, Austria, on Wednesday. The Tottenham Hotspur forward was replaced by midfielder Lee Jae-sung in the 60th minute, when South Korea were trailing 5-0.

Son is now in Prague for South Korea's friendly against the Czech Republic on Sunday. Before entering the team's first training session Thursday, he admitted his behavior was wrong and apologized to everyone who may have been disturbed by his actions.

"I know we are a good team, but I was furious when we collapsed like that," Son said. "I was also mad at myself for getting overwhelmed by the opponents, and I expressed my feelings rashly. I'm sorry."

Son had little impact against Spain. Starting as a left-wing forward, the 23-year-old had a chance to put the South Koreans up in the eighth minute when he took the ball on the left of the penalty area, but his left-footed shot went over the net. Son, with the rest of his teammates, then went silent before a second-half substitute Ju Se-jong bagged a consolation goal in the 83rd.

"Head coach Uli Stielike said that he is responsible for the result, but it is the players who were on the pitch," Son said. "I think it's important for each player to think about what went wrong in the match."

Son, who has 16 goals in 47 matches for South Korea, said South Korea needs to turn the tide and start again. He added that the players are working hard to overcome the crushing defeat.

"Instead of losing by the score of 1-0 or 2-0, I think taking a big defeat like this will teach us more lessons," he said. "Since we are not robots, we can't always perform well. But because we represent the country, we are putting our best efforts forward."

The former Bayer Leverkusen forward vowed to perform better against the Czech Republic. The South Koreans have never beaten the Czechs, with three draws and a loss in their head-to-head record.

"We have good attackers on our team, and I believe in all my teammates," he said. "We will show a better performance than we did against Spain." (Yonhap)