In the 2025 U23 Southeast Asian final, a special detail from the technical area of U23 Vietnam attracted a lot of attention. That was the fact that fitness coach Yoon Dong-hun kept waving a white scarf close to the sidelines.
In fact, this action was not random but was part of the tactical signal system of the U23 Vietnam coaching staff.
The first time, Mr. Yoon raised the scarf in the 38th minute, right after Cong Phuong's opening goal. In the 77th minute, when U23 Indonesia was preparing to make a strong throw-in from the left wing, he repeated this action when raising the turban and rotating it. On the field, the players immediately pushed up their formation, tightening the midfield area.
When asked about this move after the match, coach Kim Sang-sik said that this was a method of communication instead of words - which was difficult to hear clearly in the large and noisy stadium space.
"Instead of shouting ineffectively, we use scarves to signal situations that need pressing or adjusting tactics," said Mr. Kim.
In fact, the Vietnamese coaching staff has applied this form since the 2024 ASEAN Cup. In an interview with the Korean media in April, Mr. Kim shared that the coaching team had set up a series of separate symbols such as "swinging the board" to signal pressure, or "weaving a scarves" to change the competition diagram.
However, the white scarf also caused some misunderstanding. A social media account thought that the Vietnamese coaching staff had taken Indonesia's scarf, a familiar tool to prepare for Robi Darwis' strong throw-ins.
Returning to the final match, with a 1-0 victory from Nguyen Cong Phuong's goal, U23 Vietnam won the championship for the third time at the U23 Southeast Asian tournament.
