Tottenham’s South Korean international is yet to carry out the two-year mandatory military service expected of his countrymen.
He could earn an exemption.
He is currently in Indonesia at the Asian Games chasing a gold medal that, along with an Olympic podium finish, is the only automatic way for a South Korean footballer to be excused.
A semi-final against Syria or Vietnam and a final against either Japan or the winner of the last-eight tie between United Arab Emirates and North Korea separate him from the pass to an uninterrupted career.
Defeat in either though and the consequences are stark and fairly immediate.
Now 26, he could expect the sort of call-up that comes with a clipper cut in the next 18 months.
Five weeks of basic training, covering military drill and combat essentials, would follow.
Previous recruits report then spending their days guarding remote, freezing mountain outposts looking out over North Korea – the rogue neighbour with whom South Korea is still technically at war with 65 years after fighting halted– and their nights in giant 40-bed dormitories.
You might presume that, in reality, things will be different. That an accommodation will be found and wheels will be greased to keep Son aboard the Premier League juggernaut.
But that is far from certain.