The Tottenham Hotspur winger is the second-most bought player ahead of the deadline of 14:00 GMT on Saturday, 28 December.
More than 266,000 new owners have brought him in after he burst into form in the last few matches.
Son has five goals and three assists in the previous four Gameweeks, producing a hefty 49 FPL points.
However, Son's 15 per cent ownership should be aware that he will then play in the Asian Cup with South Korea after the United fixture.
The Asian Cup final takes place on Friday, 1 February.
If South Korea remain in contention at that point, Son is expected to be absent until Gameweek 26, which takes place the following weekend.
The Spurs man is not the only FPL regular to take part for the Asian Cup.