Son was not on the South Korean team that won a bronze medal at the 2012 London Olympics and a gold medal at the 2014 Asian Games. He represented South Korea at the 2016 Rio de Janeiro Olympics, but South Korea suffered a quarterfinals exit.

To extend his impressive career in Europe without interruption, grabbing the gold at the 2018 Asian Games has become the most important mission for Son. He is currently contracted with Spurs through June 2020.

If Son fails to win a gold medal, his stint with the English Premier League club will have come to an end unless he actually wants to serve the military service like every other man in the country. Should he return home from the Asian Games without the gold, Son's next step would probably be looking for ways to join military football clubs in South Korea.

South Korean footballers can complete their national duty by playing for Sangju Sangmu, the club run by the Korea Armed Forces Athletic Corps., or Asan Mugungwha, the club run by the national police. Sangmu are currently in the top-flight K League 1, while Mugunghwa are in the second-tier K League 2.

To join these two clubs, however, a footballer must play in the South Korean league in the previous season before making a debut for Sangmu or Mugungwha, and he needs to submit an application no later than age 27. 

If Son wants to join Sangmu or Mugungwha, he needs to return home next year to fulfill application requirements. This makes the 2018 Asian Games as the last promising opportunity for him to earn a military service exemption since winning medals at the 2020 Tokyo Olympics would be much more difficult.

Son was previously classified as "grade four" under the military conscription law, which makes him available for social service personnel. Football players who receive this grade can play in the K3 League, the de facto fourth division in the South Korean football league system, while commuting from their home. However, the competitiveness of the league will be a problem for a player like Son.

Son, who has 23 goals in 70 matches for South Korea, has yet to comment on his Asian Games selection. He left for London on Monday to prepare for the new season with Spurs. (Yonhap)