Vietnam U23 Meet South Korea U23 in Asiad 2026 Quarterfinal: The Locker-Room Door Opens Under Japan's Rain

The defeat to Vietnam U23 against Uzbekistan U23 ended as the sky had already darkened. I stood in the corridor leading down to the locker room, hearing studded boots clatter on the damp concrete floor, and the sound of someone setting a water bottle down on a bench a little too hard. At the Asiad, the corridor is not as long as at the Chengdu stadium, but that sound is very familiar. It is not the sound of a team that has fallen apart. It is the sound of a team swallowing something back in order to prepare for the next match. Three days from now, at 17:30 on September 25, in Japan, Vietnam U23 will step into the quarterfinal of the men's football tournament at the 2026 Asian Games. The opponent is defending champion South Korea U23. The rain of that year washed away many things, but it did not wash away the memory of one summer — and I believe that in that locker room, there are players remembering exactly such a summer. This match has a deep layer of water beneath it that the scoreboard does not reveal. At the AFC U23 Asian Cup 2026 in Saudi Arabia last January, South Korea U23 lost to Vietnam U23 6-7 in a penalty shootout, after the two sides drew 2-2 over 120 minutes in the third-place playoff. It was a result that forced both football nations to look at each other again. But seven months later, the picture of squad strength has clearly flipped. At the 2026 Asiad, Vietnam U23 have weakened because of the absence of Dinh Bac along with a few key players in defense. Meanwhile, South Korea U23 are far stronger: the team from the Land of Kimchi have added 9 new players currently playing in Europe plus 3 overage players. That is not a small reinforcement. That is a change of the entire spine. With such superior strength, South Korea U23 beat Qatar U23 4-1 and Saudi Arabia U23 2-0 to reach the quarterfinals as winners of Group D. In a tournament setting where matches are only days apart, a team advancing with two wins by two or more goals speaks to stability, not just moments. The physical strain at the Asiad is very different from a pure U23 tournament. Dense match schedules, travel between cities, contrasting climates — all of it wears players down. For a team that has just changed nearly half its lineup, the question is not who is better, but how long that new framework takes to play as one block. South Korea have time. Vietnam have memory. And in knockout matches, both of those things carry value. The first thing I noticed when reviewing footage of South Korea U23's 2-0 win over Saudi Arabia U23 was the tempo. They do not play fast continuously. They choose the moment to accelerate, then rein it back in, pulling the opponent out of their defensive block. The 9 players currently playing in Europe give them something that Asian youth football often lacks: the ability to keep the ball under pressure and make decisions in a split second. Add 3 overage players — including captain Lee Gi Hyuk of Gangwon FC — and South Korea have a sturdy spine running from the back upward. Lee Gi Hyuk can play both center-back and defensive midfielder. He suffered bruising on his shin after a collision in the 27th minute against Saudi Arabia U23 but still played the full match, and is fully capable of starting against Vietnam U23. That kind of player is usually the one who keeps the rhythm for the whole system — not the goal scorer, but the one who decides whether the team stands high or low. Notably, it was Lee Gi Hyuk himself who spoke up to warn his teammates. Speaking to The Chosun, he said: "Vietnam U23 have just suffered a defeat to Uzbekistan U23. So they will enter the quarterfinal with very high determination. Therefore, I reminded my teammates that they must not be careless and must always maintain a high level of focus." A captain saying that is not to please the opponent. He says it because he knows what happened in Saudi Arabia. The Korean press is not taking it lightly either. Sports Hankook warned: "Even though coach Kim Sang Sik is not present on the Vietnam U23 bench, South Korea U23 must absolutely not be careless." The newspaper assessed that Vietnam U23 still possess traits that can trouble South Korea U23, especially their ability to organize defense and transition quickly into attack. And they analyzed it bluntly: "Pragmatic defending, fierce pressing in midfield and quick counterattacks into the spaces on both flanks are Vietnam U23's weapons. Their most fearsome quality is not the names of the players, but their enduring physical foundation and a mentality with nothing to lose." That is a very carefully read sentence. Because where are South Korea strongest? In midfield, where they circulate the ball and control the rhythm. If Vietnam press exactly in that zone, they do not need to win the ball often. They only need to make each pass from South Korea a little more expensive. In terms of status, this is not the first time Vietnam U23 have walked into a match everyone thinks they will lose. What is different at the 2026 Asiad is that they are no longer at full strength. The absence of Dinh Bac in attack means losing an anchor for holding the ball; the thinning of the defense means losing stability in organizing the defensive block inside the box. But a team missing players sometimes defends more disciplined, because they have no choice but to stand in the right positions. The key point lies on the flanks. With Vietnam's defense thinned by absences, the flank spaces are the most exposed. But those same spaces are also the starting point of quick counterattacks. South Korea push their full-backs high to support the attack, and when they lose the ball, they need Lee Gi Hyuk to cover. Lee Gi Hyuk has a bruised shin — that small detail, in a knockout match, could be the pivot for a sprint in the 85th minute. I have stood outside locker-room doors long enough to know that teams missing players often find a different structure, more labored but more disciplined. From zero, I know that the locker-room door only opens when you dare to stand waiting in the rain — and this time, that door is waiting for a Vietnam team that must rebuild itself. The thing outsiders often misunderstand: they think the penalty win last January was a stroke of luck, and therefore will not repeat. But I think the opposite. A penalty shootout stretching to 6-7, after a 2-2 draw over 120 minutes, is not a product of luck. It is a product of something harder to train than technique: calmness under extreme pressure. Teams capable of beating South Korea at that are usually carrying a kind of character that data analysis struggles to measure. And here is the second counter-intuitive point: the absence of coach Kim Sang Sik from the coaching bench is not necessarily an absolute disadvantage. The players no longer have anyone to glance at whenever they get stuck. Sometimes, that very moment forces the team to talk to each other on the pitch. South Korea enter the match as the stronger team. And the burden of the stronger team is that they must win. Vietnam enter as the team that just lost the previous match. And the freedom of having nothing left to lose is something no tactical board can weigh. At 17:30 on September 25, in Japan, we will find out whether an enduring physical foundation and a nothing-to-lose mentality are enough to offset the gap in squad strength. I write about the ball, but I keep the rhythm with the hearts of the people who play it. And the heartbeat of a team that just lost, standing before the defending champion, tends to beat in a very unpredictable way.