'Potential heartbreaker': South Korea sweats on Son's World Cup fate
His club Tottenham said the forward suffered a fracture around his left eye and will have surgery, less than three weeks before the country's opening match in Qatar.
The nasty injury, which Son picked up in a Champions League win over Marseille earlier this week, has put his World Cup in doubt.
Spurs and the Korea Football Association are keeping tight-lipped about his chances of making it.
"Regarding Son Heung-min's status for the World Cup, we will have to monitor his progress after the surgery," the KFA said.
"We will remain in touch with Tottenham's medical staff."
The Daily Telegraph reported that Son had four fractures to his eye socket, with surgery brought forward to Friday to give him more time to recover.
South Korea's opening match of the World Cup is against Uruguay on November 24. Paulo Bento's side will also face Ghana and Portugal in Group H.
Son is not only the side's best player, but captain and talisman. He has 35 goals in 104 international games, including nine in his last 14.
In October last year he came 11th in the voting for the Ballon d’Or, the prestigious award for the world's best player, and last season jointly won the English Premier League's Golden Boot for most goals scored.
Though he is yet to lift a trophy at club level, in 2018 he led South Korea to gold at the Asian Games.
Underlining just what he means to South Korea's chances, angry fans posted thousands of abusive messages, some racist, on the Instagram account of the Marseille defender who collided with Son to cause the injury.
"Dirty gross player. You messed up our World Cup," one message aimed a Chancel Mbemba (28) read.
Son's World Cup fate dominated the sports pages of South Korean newspapers on Friday, including one that featured a detailed diagram of a human skull to show where the injury was.
'Catastrophically devastating'
South Korean football writer Steve Han called Son's possible absence "a potential heartbreaker".
"Son is an integral part of Bento's side both on and off the pitch," said Han.
"What makes this injury a potential heartbreaker, though, is that Son's performance for Korea has been improving gradually over the last couple of years.
"And he has added lethal free-kicks to his game, which could be Korea's main source for goals in Qatar."
Television commentator Park Moon-sung said that Son was so important that he could even go to Qatar in a non-playing capacity.
"He has such a significant presence on the national team," said Park, according to Yonhap news agency.
"There should be ways he can help the team as a reserve," he said. "He can also be a cheerleader on the bench for some younger guys."
At age 30, Son could also be looking at his last chance to represent South Korea on the world stage while at the peak of his powers.
"For all his greatness, he has yet to create that landmark moment for Korea," said Han.
He added that missing out on this winter's tournament could rob Son of a chance to emulate the heroes of 2002, when South Korea made the World Cup semi-finals on home soil.
"Park Ji-sung was a South Korean football legend not only because of his accomplishments in Europe with Manchester United, but also because of the landmark moments that he created for Korea," said Han.
That included Park's winning goal against Portugal in 2002 to propel South Korea into the last 16 for the first time.
"With Portugal again being Korea's last opponent of the group stage for the upcoming World Cup, the hope was for him (Son) to replicate the footsteps of Park," said Han.
"It would be catastrophically devastating for him to miss out on that opportunity at this stage of his career."