Vietnam cruised past Timor-Leste to accomplish their opening objective at the 2026 ASEAN Cup while underlining their formidable strength. Yet, as in previous matches, their defence still offered little sense of complete reassurance.

Genuine concern

Judging by the scoreline alone, Vietnam appeared to have enjoyed a straightforward opening match against Timor-Leste at the 2026 ASEAN Cup. But what unfolded on the pitch exposed a relatively familiar problem for Kim Sang Sik's side.

That problem is none other than a defensive system that has yet to become truly solid. Even against a considerably weaker Timor-Leste side, Vietnam still found themselves facing genuine threats to their goal.

Statistics showed that Timor-Leste created at least three or four clear-cut chances that could have beaten Le Giang: Da Silva headed over the bar in the 58th minute, while chances in the 62nd and 85th minutes saw the ball go narrowly wide from remarkably open positions or strike the post.

There was more in the 89th minute. From a corner, Juvito Moniz was left completely unmarked after Van Hau failed to track him and was able to head toward goal. Pereira then had an opportunity to score from the rebound from around five metres out, only to fire wide.

The concern is that this is not the first time Vietnam's defensive system has run into such trouble. Similar gaps had already emerged in the friendly against Myanmar, particularly when the opposition switched quickly from defence to attack.

A trap set by Kim Sang Sik?

For an experienced coach like Kim Sang Sik, the shortcomings in his defence could hardly have gone unnoticed. What makes the situation intriguing, however, is how the South Korean coach chose to respond.

Rather than introducing a genuine holding midfielder to close the space in front of the defence - the kind of role Doan Ngoc Tan had previously performed to great effect - the Vietnam coach took a different approach.

Thanh Chung, Tien Anh and Van Vi were withdrawn in turn for Viet Anh, Tuan Tai and Le Van Do. Essentially, these substitutions appeared to be more about experimentation than fixing the problem.

In other words, Kim Sang Sik seemed willing to let Vietnam continue operating within the same system despite the gaps that kept appearing between the two lines. In fact, Timor-Leste went on to create even more dangerous opportunities.

That is precisely why some observers may be tempted to consider another possibility: Kim Sang Sik could be laying a trap for stronger opponents awaiting Vietnam, such as Indonesia or Singapore.

In that scenario, the South Korean coach may not want his opponents to sit deep, defend in numbers or “park the bus,” a strategy that could make it difficult for Vietnam to build attacks and potentially drag them into the kind of deadlock they have encountered before.

And there may be no better way to discourage opponents from adopting an ultra-defensive approach than allowing them to see signs of vulnerability in front of Vietnam's goal - giving them an incentive to push higher up the pitch and attack.

Indeed, after scoring their opening goals, Vietnam eased the tempo and allowed Timor-Leste more possession and opportunities to attack... before adding six more goals and completing a 7-0 victory.

Of course, for now, this remains only a theory. What can be seen is that Vietnam's defence remains a significant concern. The real answer may only emerge when the ASEAN Cup brings Vietnam up against opponents of comparable quality and strength, forcing every tactical calculation to finally come into the open.

Duy Nguyen