Vietnam U23 Face South Korea U23 in the Asiad 2026 Quarter-Finals: The Space Behind the Full-Backs Is the Real Blade

In January 2026, in a city in Saudi Arabia where the wind moved through the stands the way it moves across empty sand, a Vietnam U23 player set the ball on the penalty spot. Nobody in the crowd could remember his name. I could, because I had written it in my notebook, just below a line of ink smeared by another rain in Moscow eight years before. The shootout ended 6-7 after 120 minutes at 2-2, and Vietnam U23 left the 2026 AFC U23 Championship with a bronze medal. A scoreboard cannot hold a heart, and football writes its poetry in exactly those places. Now that notebook turns a new page: 17:30 on 25 September, in Japan, Vietnam U23 meet defending champions South Korea U23 in the quarter-finals of the men's football tournament at the 2026 Asian Games. The context has shifted since January. At the AFC U23 Championship, Vietnam U23 beat South Korea U23 on penalties. But at the 2026 Asian Games, Vietnam U23 arrive with a patchwork defence: Đình Bắc is absent, along with a few key players in the back line. On the other side, South Korea U23 have added nine players currently playing in Europe and three overage players. They beat Qatar U23 4-1 and Saudi Arabia U23 2-0, reaching the quarter-finals as winners of Group D. The team Vietnam U23 once beat in January is now a very different squad. What stands out is that their captain is the one issuing the warning first. Lee Gi Hyuk, one of South Korea U23's three overage players, currently at Gangwon FC, told The Chosun: "Vietnam U23 have just suffered a defeat to Uzbekistan U23. So they will come into the quarter-final with enormous determination. That is why I reminded my team-mates that we cannot afford to switch off and must maintain full concentration." He can play both centre-back and defensive midfield, picked up a bruised shin in a collision in the 27th minute against Saudi Arabia U23, finished the match, and is fully available for the next game. The Korean press is not taking it lightly either. Sports Hankook warned: "Although coach Kim Sang Sik is not on the bench for Vietnam U23, South Korea U23 must absolutely not be complacent." The outlet pointed out that Vietnam U23 still possess traits that can trouble their opponents: "Pragmatic defending, aggressive pressing in midfield and quick counter-attacks into the space on both flanks are Vietnam U23's weapons. Their most frightening quality is not the reputation of their players, but their durable physical base and a mentality with nothing to lose." Reading those lines closely, I see the Koreans telling half the truth. My notebook still holds a few drops of Moscow rain. The other half sits where no press conference reaches. In it, every page about Vietnam U23 begins with a question about structure rather than names: how many players does this team defend with, and when does it dare to open up? At the AFC U23 Championship in January, that back line sat deep, fought duels in midfield, then hit long diagonal balls to the flanks. Nothing mystical. One thing is so simple that people skip past it: they defended as if every phase were the last phase of the second period of extra time. At the 2026 Asian Games, that structure faces a different test in kind. South Korea U23 are no longer a side that circulates the ball slowly and waits. Nine Europe-based players bring a different tempo, and three overage players — Lee Gi Hyuk among them — form a spine through the middle. The ball travels forward in few touches, and the full-backs push up almost in unison. That is why their two group games ended 4-1 and 2-0: not because they shot often, but because they kept the ball in the opposition half for long stretches. Yet that very mechanism opens the space Sports Hankook calls "the space on both flanks". When both South Korea U23 full-backs advance, the area behind them grows wide enough that a 30-metre pass can turn it into a chance. With a defence that has already lost several pillars, Vietnam U23 will struggle to hold the same low block for 90 minutes and still have the legs to burst out at that exact moment. The problem lies not in the tactical idea, but in the legs of the people executing it. On an empty pitch at night, I hear the ball breathing. It reminds me that a team does not lose its identity merely by missing players; it loses the ability to turn that identity into goals. This is where the story is usually told wrong. After the penalty shootout win in January, people drew the lesson that Vietnam U23 can endure and then win. But enduring and competing are two different things. A match a team survives by clearing the ball into touch and waiting for penalties is a match that has placed its fate in someone else's hands. The blind spot of collective memory sits right there: we remember the medal, and forget that it was decided by 12 kicks, not by 120 minutes of defending. There is another matter few mention these days. South Korea U23's strength at the 2026 Asian Games is largely borrowed strength. Three overage players and nine Europe-based faces are fitted into a squad within weeks, enough to win results, not enough to build a generation. In youth football, plenty of players from both countries have to leave their parent clubs on loans with obligation-to-buy clauses — a mechanism that leaves small clubs losing the players they developed while big clubs receive finished products. On the bench, the shift to a back three is often presented as a tactical advance. Look closer, and it is usually a coach insuring himself: one more centre-back, one fewer attacking midfielder, and a defence that looks less fragile in the bulletins. At 17:30 on 25 September, when the whistle blows on a pitch in Japan, two teams will line up with two different understandings of the same round ball. Sixty-nine years on, I still believe a beautiful pass is a declaration of love. They call me a dreamer. But the ball has never hidden anything from me. In my notebook, beside the names of players nobody remembers, I have left a page blank for this match — because that page will be written by the feet of someone whose name no one knows.