Rarely can a footballer have been under so much pressure to win as Heung-min Son in the Asian Games final on Saturday.

The South Korea captain is not just playing for his country: he is playing for his career, his reputation and his life; or, at least, the next few years of it.

If South Korea retain the gold medal against rivals Japan in Indonesia, the Tottenham forward and his team-mates will earn precious exemption from their country's 21-month military service - mandatory before the age of 28.

"It's a subject we talk about a lot," Mauricio Pochettino, the Spurs manager, said on Friday. "He was worried and he wants to deliver the victory and win because he wants to avoid [conscription], of course."

Son, who turned 26 in July, has rarely spoken publicly about the prospect of conscription but he has been unable to hide his angst at the situation in the past.

A medal in the 2016 Rio Olympics would have been enough to earn a reprieve, but he missed a crucial chance in South Korea's 1-0 defeat to Honduras in the quarter-finals.

He spent the rest of the day locked in his hotel room in tears and refused to eat. "It was sad to see," said South Korea's Olympic coach Shin Taeyong.

Son was reduced to tears again when South Korea lost to Sweden at this summer's World Cup to confirm their group-stage exit. The 2002 squad earned exemption for reaching the semi-finals on home soil, and this year's class may have been granted a reprieve for reaching the knockouts.

Back home, hopeful public calls for Son to avoid the draft for his part in the brilliant win 2-0 over holders Germany in their final group game fell on dear ears.

The situation is even more frustrating because Son could have earned exemption four years ago, when South Korea won the 2014 Asian Games, but his former club Bayer Leverkusen refused to release him for the U-23 tournament. Spurs have been much more accommodating and, just as at the Olympics, he is one of three over-age wildcard in the 20-man squad to face Japan.

If South Korea lose on Saturday, Son's routes to avoiding conscription are complex. He will play in the Asian Cup in the United Arab Emirates in January but winning the continent's most prestigious tournament does not normally earn exemption.

Son could attempt to delay his service to play in the 2020 Olympics, which will begin shortly after his 28th birthday, but he is unlikely to want to postpone the issue for another two years, particularly when South Korea could be outsiders to medal in Tokyo.

Delaying national service until he is 35 would be possible by applying for dual citizenship in Germany, where he moved as a teenager to join Hamburg, but the public backlash in South Korea to such a move would be vicious.

Arsenal's Park Chu-young delayed service after earning Monaco residency and faced fierce public criticism and axing from the national team squad.

"If - if - something wrong happens [on Saturday], it's not in our hands," said Pochettino. "But he's our player. We look after him and we care about him but we're positive and we hope we can score and win and avoid [conscription], be happy and enjoy his career here with us."

If South Korea do lose on Saturday, Pochettino will face a challenge to revive Son for the remainder of the season and, whatever the result, the Argentine will need to manage the forward carefully in the next few months.

South Korea coach Kim-Hak Bum had planned to rest Son for the Asian Games group stage but he was needed from the bench as they slipped to a shock 2-1 defeat to Malaysia in their second game, before playing from the start, and scoring, as they booked their place in the last-16 win a 1-0 win over Kyrgyzstan.

There has been no rest for Son in the knockouts and he will have played four games in 10 days, including 120 minutes in the quarter-final victory over Uzbekistan, after Saturday's final.

If such a gruelling programme in the sweltering heat on dreadful pitches was not enough, Son will travel straight from Indonesia to South Korea for the senior squad's friendlies against Costa Rica and Chile.

Spurs have, at least, blocked Son from playing in November's two friendlies and the first two group games at the Asian Cup - against the Philippines on January 7 and Kyrgyzstan four days later - as part of the agreement for releasing him for the Asian Games but he has had a gruelling summer and autumn schedule, having already competed in the World Cup and Spurs' pre-season tour to the US.

Son has reassured Pochettino he will be ready to play when he returns to Spurs in mid-September and the hope on all sides is that, by then, he is finally free to fulfil the five-year contract he signed with Spurs in July. It all comes down to Saturday.