A gold medal in Indonesia is Son's last chance to earn exemption from his country's mandatory 21-month military service but – given the shoddy state of the pitches – South Korea U-23 coach Kim Hak-bum had planned to save his star player for the knockouts.
But the shock 2-1 defeat to Malaysia forced a rethink and Son scored the only goal after starting the defending champions' 1-0 win over Kyrgyzstan on Monday.
The victory set-up a tricky last-16 clash with Iran – who, like South Korea, have won gold three times previously – on Thursday.
Afterwards Son said: "I always follow Tottenham – I was very happy because Lucas [Moura] scored his first Premier League goal for us, and Harry [Kane] scored in August.
"I'm following wherever I go. When they play Manchester United [on Monday] I will support them."
Spurs gave Son special dispensation to play as an overage wildcard in the U-23 tournament, shortly after he signed a new five-year deal with the club.
"I can't say I'm 100 per cent sure to win the gold medal. We are on the way to make something, and to win some trophies," he said. "But I'm not thinking about it already, the final."
Son was rested for the 6-0 win over Bahrain and the defeat to Malaysia but he returned to the XI on Monday, even though South Korea were all but guaranteed a place in the last-16 prior to kick-off – with only an 11-0 defeat preventing their passage.
In Son's absence, Lucas and Erik Lamela made their cases for inclusion in Spurs' 3-1 win over Fulham on Saturday, with the former scoring a brilliant opener and the latter coming off the bench to bag a fine assist.
"You know, it doesn't matter who plays – I will be ready when I get back to Tottenham as well," Son said. "[Having] conversations with Lucas Moura, Eric Lamela, Harry, we have a lot of good players. I think this will make our team stronger and stronger.