Vietnam vs Thailand: The 5-3-2 and Kim Sang Sik's Gamble of Trust

In the last three matches, Vietnam's PPDA in the regional qualifiers has increased significantly, a sign that the national team's defensive block is dropping deeper and applying less pressure. That number does not appear in any official report, but it is something I recorded in my notebook while sitting in the stands at Thong Nhat Stadium during the 1-0 win over the Philippines. It was a win, but the kind of win that makes you rewatch the footage at two in the morning to find an answer to a single question: how much does this team trust each other?

The answer seems to be rewritten by Coach Kim Sang Sik with an entirely new formation. Ahead of the clash dubbed the Southeast Asian derby with Thailand, he switched from a 3-4-3 to a 5-3-2. This is not a revolutionary tactical innovation. It is a pure defensive reaction, a way to limit damage against a superior opponent in terms of ball control, especially when the midfield left clear concerns in the previous match.

The context of this change cannot be separated from the injury list. Five key players are absent, including naturalized striker Nguyen Xuan Son, who is still recovering. Losing a striker capable of creating breakthroughs and stretching the opposition defense forces Kim Sang Sik to build a different structure. He chose three center-backs, a three-man midfield that has never started together, and a strike partnership of Dinh Bac and Tai Loc. On the flanks, Phan Tuan Tai and Truong Tien Anh are tasked with providing width in both attack and defense.

The key lies in midfield. The combination of Cao Pendant Quang Vinh, Le Pham Thanh Long, and Vo Hoang Minh Khoa is an unverified gamble of trust. They have never started together in any official match. In a tense rivalry like Vietnam vs Thailand, a lack of cohesion often leads to positional gaps and disjointed pressing coordination. Thailand possesses a very strong midfield, with Chanathip Songkrasin moving cleverly into half-spaces and Supachai Chaided offering a formidable physical presence.

The 5-3-2 is not just a reaction to injuries; it is an admission that Vietnam no longer trusts its ability to control the game against Thailand. Three center-backs create central solidity but reduce attacking support from the back. The two strikers, Dinh Bac and Tai Loc, must operate in tight spaces, relying on quick transition passes from midfield and the advanced runs of the two wing-backs. That is the classic structure of counter-attacking football, one I saw Saudi Arabia use to beat Argentina at the 2026 World Cup with only 31% possession.

But there is a difference. Saudi Arabia in 2026 was a team that had trained together for years, with a midfield that understood each other's movements down to the step. Vietnam now is not. The combination of Cao Pendant Quang Vinh, Le Pham Thanh Long, and Vo Hoang Minh Khoa is an unproven trio. In the first half, if Thailand presses high and circulates the ball quickly on the flanks, this three-man midfield will have to run a lot to cover gaps they have not yet developed the habit of covering for each other. My experience following matches shows that new midfields often take 20 to 30 minutes to find each other, and in that window, high-quality opponents will exploit it ruthlessly.

There is a counter-intuitive angle here. We often think that more defense equals more safety. But for Vietnam, switching to a 5-3-2 may actually be a riskier gamble than keeping the 3-4-3. The reason is that when you play with five defenders and three midfielders, you create a crowded defensive block but also narrow the attacking space. If Thailand scores first, Vietnam will face great difficulty transitioning from defense to attack, because the attacking players will be isolated. Meanwhile, playing a 3-4-3 with four midfielders gives the team better ball retention and the ability to create more sustained pressure.

It is noteworthy that no quantitative data, whether xG or PPDA, was provided to support the claims of "midfield confusion" in the Philippines match. Those assessments are qualitative, and we should treat them as such. xG has been overused in modern football, and it does not explain a coach's dressing-room decisions, a player's actual form, or referee standards. Therefore, when evaluating Kim Sang Sik's gamble, we must acknowledge that we are assessing a plan, not a verified reality.

Thailand enters this match with a convincing 4-0 victory. That result reflects alignment between outcome and performance, something Vietnam's 1-0 win did not have. Thailand did not just score; they controlled the game in a way that left the opponent unable to respond. Their possession of players like Chanathip and Supachai, who can change a game with a single moment, poses a major challenge to Vietnam's three-man defense. Chanathip's movement in the half-spaces will test the center-backs' covering ability, while Supachai will challenge their physical strength in aerial duels.

Public pressure is weighing heavily on Kim Sang Sik. His four changes to the starting lineup compared to the Philippines match show instability in finding the optimal eleven. If Vietnam loses or performs poorly, narratives of "tactical error" and "overly negative defense" will flood the newspapers. This is pressure any coach faces when leading a national team against a historic rival.

But there is another aspect that receives less attention. Kim Sang Sik's choice of a midfield that has never started together is not just a tactical issue; it is a matter of trust. He is placing trust in young players like Cao Pendant Quang Vinh and Vo Hoang Minh Khoa, who may not have been tested at international level but have development potential. This is a decision that invests in the future, even if it may put the team at risk in the present.

In the newsroom, I am often called the mediator. But mediation does not mean vagueness. It means seeing both sides of an issue and finding the intersection. In this case, the intersection lies in this: Kim Sang Sik is betting on collective defensive capability and efficient transition moments, rather than trying to confront Thailand directly in midfield. It is a logically sound choice, but the risk lies in the execution capability of a new midfield.

When the opening whistle blows, the question is no longer how this team controls the game. The question is how much this team trusts each other. Trust that the three new midfielders will cover for each other when Thailand attacks. Trust that the two wing-backs will push forward at the right moment and drop back at the right time. Trust that Dinh Bac and Tai Loc will capitalize on the few transition moments.

Thong Nhat Stadium is not grand; it only has people brave enough to cry mid-match. And in a Southeast Asian derby, trust between people is something that can last longer than the final result.

The next signal I will monitor is not the scoreline, but how the three-man midfield reacts in the first 20 minutes when Thailand presses high. If they maintain their distances and cover for each other, Kim Sang Sik's gamble could succeed. If they leave gaps between the lines, everything could collapse before the first half ends. Football does not need control; it needs to be trusted. But trust must always be built through concrete actions on the pitch.