Monterrey (Mexico) (AFP) - There was a row with the media, a drone buzzing a crucial training session and then captain Son Heung-min dropped by a deeply unpopular coach in a gamble that backfired.

Now South Korea are sweating on their place in the World Cup knockout rounds after a surprise 1-0 defeat to South Africa on Wednesday.

It had all started so well as Hong Myung-bo’s side fought back to beat the Czech Republic 2-1 in their opening match of the tournament.

But 1-0 defeats to the co-hosts, Mexico, and South Africa have left the Koreans awaiting their fate as one of the best third-placed finishers.

“I think we have to consider the big picture and figure out where things went wrong,” Son said following the loss to a South Africa side who came into the competition ranked 35 places below South Korea.

“No one is more upset than the players themselves,” added Son according to Yonhap News Agency.

“But I can honestly tell you that we’ve had absolutely zero issue with our team atmosphere.”

Needing just a draw to guarantee their place in the last 32, Hong caused a shock by starting Son – widely regarded as the best player in Asian football history – on the bench.

South Korea were toothless in the first half, and Hong brought the veteran attacker on at the break.

But they were no better for it, and Thapelo Maseko struck just after the hour to propel South Africa into the World Cup knockouts for the first time.

At the post-match press conference, one reporter asked Hong if the players had food poisoning – such was the incredulity at the insipid display.

“I guess I made the wrong decisions and that was the reason why we had a bad result,” said Hong, who captained his country to the semi-finals of their home 2002 World Cup.

“Nothing more, nothing less.”

- Son ‘sorry’ -

Expectations back home were low coming into the World Cup, with fans unimpressed by Hong and ill-feeling towards the Korea Football Association.

Despite a stellar playing career Hong’s many detractors pointed out that during his first stint as coach South Korea exited the 2014 World Cup winless in the group stage.

He is accused of muddled tactics and failing to get the most out of a squad that includes Paris Saint-Germain playmaker Lee Kang-in, Bayern Munich defender Kim Min-jae and Feyenoord midfielder Hwang In-beom.

According to Yonhap, there was a flashpoint involving Hwang and the celebrating South Africa players after the game when he told them to “show some manners”.

Son, dropped for a World Cup match for the first time, said: “I feel sorry to my teammates that I didn’t give them much help on the pitch.”

At what will surely be his last World Cup, Son is on a downward trajectory – hardly a surprise for a player who turns 34 next month.

- Spying fears -

South Korea’s World Cup has been tinged by a sense of disharmony.

A standoff ensued between the players and South Korean media after members of the press were overheard appearing to mock Son’s military record.

Almost all able-bodied men in South Korea are obliged to serve in the military for at least 18 months, but that can be changed in certain circumstances.

Former Tottenham attacker Son, who now plays for Los Angeles FC, was able to fulfil his obligations with three weeks’ basic training and around 500 hours of community service.

After the comments came to light, the South Korea squad reportedly boycotted interviews with the domestic press.

Then, before the defeat to Mexico, a drone was spotted flying over South Korea’s training session, prompting fears of spying.

The drone was reportedly brought down by Mexico’s military using radio signals.

“Fortunately it was right before we practised our tactics, so it did not impact us significantly,” said Hong.

“But, while we were preparing for the match, that was the most important timing.”