Tottenham Hotspur attacker Son Heung-Min has apologised for his behaviour during South Korea's 6-1 friendly defeat to Spain on Wednesday, saying he was "furious" with the team's performance.
Son flung a towel towards the bench after being replaced by teammate Lee Jae-Sung on the hour, with South Korea trailing 5-0 at the Red Bull Arena in Salzburg.
The 23-year-old said he had been rash and stressed that the players had to take responsibility for their capitulation to the defending European champions.
"I know we are a good team, but I was furious when we collapsed like that," Son told the Yonhap News Agency.
"I was also mad at myself for getting overwhelmed by the opponents, and I expressed my feelings rashly. I'm sorry.
"Head coach Uli Stielike said that he is responsible for the result, but it is the players who were on the pitch. I think it's important for each player to think about what went wrong in the match."
South Korea struggled to cope throughout the match as forwards Nolito and Alvaro Morata both scored twice, with Cesc Fabregas and David Silva also on the scoresheet.
Se-Jong Ju scored a late consolation for South Korea, and Son said: "I think taking a big defeat like this will teach us more lessons.
"Since we are not robots, we can't always perform well. But because we represent the country, we are putting our best efforts forward."