South Korea captain Son Heung-min has asked fans to forgive teammate Lee Kang-in after the midfielder apologised "sincerely" for his involvement in an altercation between the pair on the eve of their Asian Cup semi-final.

Son played against Jordan with the index and middle fingers of his right hand strapped together as the Koreans were stunned 2-0, a result which extended their 64-year wait for a third Asian title and saw coach Juergen Klinsmann fired. 

The Korea Football Association later confirmed a British media report that Lee left a team dinner early with some of the younger members of the squad to play table tennis, leading to an argument with Son, who viewed the dinner as a chance for the team to bond before the match.

Tottenham Hotspur forward Son was left with a dislocated finger as players were being pulled apart.

Paris St Germain midfielder Lee has come in for heavy criticism in South Korea, where Son remains the country's most popular athlete.

"Kang-in has done sincere soul-searching about his actions and offered a sincere apology to all the players on the national team, including myself," Son said in a post on Instagram on Wednesday.

"To prevent Kang-in from doing such a wrong behaviour again, all of our players, as seniors of the national team, will take special care from his side so that he can grow into a better person and player.

"Since that incident, Kang-in is going through a very difficult time. Please forgive him just once more with a generous heart."

In a post on Instagram, Lee said he had travelled to London to apologise to Son in person.

"That day, I did something I should never have done at dinner. Looking back again, it was something I should never have done. I deeply regret it ...," Lee added.

"I promised to have a more proper attitude and courtesy when dealing with my seniors and colleagues. I would like to thank them once again for accepting and embracing my apology."