Vietnam's number-one assistant seat empty for the fourth time: the set-piece problem and the continuity gap

Minute 67 of the third-place match, a corner from the right. I was sitting close enough to the tribune to see what television could not carry: inside the box, nobody looked like they believed the ball would go in. They made their runs out of habit, jumped out of habit, and the ball left the goal out of habit. That moment made me think of a name absent from Vietnam's matchday squad.

That name is Lee Jung Soo.

A football story never begins at the first minute. It begins at a training-ground corner, where a man stands outside the touchline with a notebook full of set-piece routines. And it ended — for Vietnam — with a number-one assistant's seat left empty for the fourth time in under two years.

Kim Sang Sik arrived as head coach and brought a familiar Korean model: a Korean captain, surrounded by Korean assistants, working like a small orchestra with the conductor in the middle. The number-one assistant — second only to him — is the pivotal post in that model, and it has changed hands again and again.

Choi Won Kwon left after the 2026 ASEAN Cup title, in early 2026, to join Thanh Hoa. Lee Jung Soo, credited especially for set-piece situations, left after about a year for Thailand. Kim Do Heon — a former Korean international who played at the 2026 World Cup — joined in late June on a short-term contract covering two tournaments, and that contract has just expired. Now the staff must find a fourth man, with the November FIFA Days window already close and two matches against Chinese Taipei and Kyrgyzstan waiting.

At the 2026 regional championship, Vietnam finished fourth and lost to Malaysia in the third-place match on October 5. For a side used to standing at the top of Southeast Asia, that is a step back. And more telling still: after Lee Jung Soo left, goals from set pieces all but vanished across the two 2026 tournaments.

Placed side by side, those two curves — results falling, personnel rotating — do not run parallel by accident. They feed each other. Poor results open the door to staff change, and staff change breaks the very continuity needed to improve results.

In Southeast Asia, the gap at the top is narrowing. Malaysia is investing more methodically, Indonesia is pushing naturalisation and youth development, Thailand retains depth. In a region where any match can turn on a single corner, losing the man who designs those corners is no small matter. It is a matter of a few points, of a deep run or an early exit.

This is where I want to pause a little longer, because most commentary circles around the question of “who will be the next assistant”, when the real question lies elsewhere.

Vietnam's problem is not losing a set-piece specialist; it is a model in which set-piece knowledge lives inside one person's head rather than inside an institutionalised coaching methodology.

Picture a corner. Someone blocks, someone attacks the near post, someone drops to the second line. Each run is a stitch in a net. When the man who designed those stitches leaves, the players still remember the movement — but forget the reason. They still run to the right place, but no longer believe in it. That is the difference between a drill and a conviction.

In modern football, a national team rarely creates chances through a single assistant alone. If set-piece goals disappear after Lee Jung Soo leaves, that points to two possibilities. Either his method was so particular that nobody could copy it — meaning it was never written down as a curriculum. Or the decline is simply the by-product of broader attacking stagnation, and set pieces are merely where it shows most clearly. Both possibilities lead to the same point: a lack of continuity.

Based on my experience watching these matches, a team that loses its set-piece sharpness usually does not lose it in the design phase. It loses it in the repetition phase. A corner only becomes a weapon after hundreds of repetitions to the point where players no longer need to think. A new assistant will bring new routines, but it takes months to install them into collective reflex. November is not long enough for that. Every day of delay in the appointment is a day subtracted from the preparation fund for the 2027 Asian Cup.

It should be added that Vietnam's set-piece goals in the earlier period were not a durable statistical phenomenon. They came in waves, depending on the quality of the delivery, on the midfield's ability to contest, and on whether the opponent had prepared. When all three variables turn unfavourable at once, even a good set-piece coach can only limit the damage, not reverse the trend. That is why I do not want to attribute the entire decline to one individual.

But I want to push back on the prevailing narrative itself.

The phrase “the fourth time” sounds like an anomaly. It is not quite that. Look closely, and those who left all departed when their contracts — short-term, tied to individual tournament cycles — expired, or when a better offer came from club level. Choi Won Kwon went to Thanh Hoa. Lee Jung Soo went to Thailand. Those are ordinary career moves in a regional coaching labour market that is moving fast. The worry lies not in the number of changes, but in the contracting model that produced them.

Every short-term contract is a farewell written in advance.

When you sign an assistant on a “see out this tournament and we will talk” basis, you are guaranteeing you will have to recruit again. You are also guaranteeing that he will not throw himself fully into a long-term project. This is the blind spot of the collective memory around the national team: we remember the names of those who left, but forget the structure that made them leave. A team run on tournament cycles will always feel provisional, even when results have not yet turned tragic.

There is one more thing rarely said. Always seeking the number-one assistant “from Korea” narrows the candidate pool, and quietly asserts that set-piece coaching or tactical analysis must be imported. That is true for now, but it is also a confession of a domestic gap. A football nation that cannot train its own number two will always depend on a number two from somewhere else. And when the two November friendlies are merely experimental, time pressure is all the more likely to push the staff toward a safe, network-based choice rather than an optimal one.

I count the seconds the Japanese way — not counting down, but counting what remains. What remains before the 2027 Asian Cup? A head coach still in place, a number-one assistant's seat still empty, two November friendlies, and a faith thinning in the stands.

The question is not who will sit in that chair. The question is whether the staff dares to write its set-piece method into a curriculum that belongs to the team, not to an individual — so that a fifth time, if it comes, is no longer a farewell.

The rain on that park never lets memory dry. But football memory only dries when we let it depend on one person. Let it depend on a system.