"Having to concede a goal at the last minute made me disappointed," he said after the match at My Dinh Stadium in Hanoi.
Facing a strong opponent, he said, Vietnam had adopted a reasonable strategy to counter their high ball play. Iraq had a better individual level, so Vietnam had to focus on a playing style, he said.
"I feel very sorry about the last-minute loss. All the players' confidence in the playing style has not brought a good result. But they had made a lot of efforts."
Playing at home, Vietnam yet faced many difficulties against a superior opponent. Iraq pressed high pressure from the beginning, making it almost impossible for the hosts to launch any attack, and causing them to make many mistakes in passing the ball too.
In the first 30 minutes, Iraq created at least three dangerous situations in front of Vietnam's goal, but goalkeeper Dang Van Lam saved the team from an early defeat.
In the last 15 minutes of the first half, Iraq created two more good opportunities, but still could not converted them into goals. Vietnam did not finish once, and had only one counterattack in the first half when Tien Linh did not handle it well, missing the opportunity to pass the ball to Van Toan who was in a more favorable position to score. Coach Troussier expressed frustation many times as he rushed to the sideline to make loud complaints when his players lost the ball or made a bad pass.
In the second half, the French coach subbed out the older players Van Toan, Tien Linh, Tuan Anh, and Que Ngoc Hai to make room for younger players Dinh Bac, Thanh Nhan, Le Pham Thanh Long, and Bui Hoang Viet Anh.
With the adjustments, Vietnam played more confidently and made several clear chances.
But in the sixth minute of injury time, Iraq scored the winning goal when Ibrahim Bayesh crossed from the right for Mohanad Ali to head it in past Van Lam.
Coach Troussier said he was disappointed with the result, but not with how the players had played and the efforts they made.
"I'm proud. They tried until the last minute against Asia's top opponent," he said.
"I often tell everyone and myself that sometimes I don't lose but learn the lesson. But I have to realize that most Vietnamese players play domestically, and in these highly physical matches, they can't play the whole match."
He said most of his personnel changes during the game were made not because of tactical reasons but because the players were exhausted.
"We can only play at high intensity for about 60 minutes, the remaining 30 minutes we have to play differently, waiting for the opponent to make a mistake."
After two matches, Vietnam got three points and ranked second in Group F, while Iraq earned six points. Indonesia and the Philippines shared the last two positions. The teams will continue playing the second World Cup qualification round next March.
The top two teams in each group will continue to the third qualifying round.
Coach Troussier said: "Of course our goal was to win the [Iraq] match, but the long-term goal is to finish in the top 2 in this round to win a ticket to continue... I respect the Philippines but I consider Indonesia to be the main opponent.
"We still have an advantage."
Questions were raised from both fans and commentators as coach Troussier continued to put reigning Golden Ball winner midfielder Nguyen Hoang Duc on the bench, like in the Philippines game.
According to the French coach, Vietnam's midfield played well during the match.
"We cannot rely on an individual to win an Asia’s top opponent. We need a synchronized team and Hoang Duc has not met the requirements." He said. "I want him to perform better in the team. In practice, I always push Hoang Duc. I believe he understands my expectations for him, I hope he gets better."
Troussier said he has his own criteria when choosing players on the field.
He said his goal is to develop the team for a bigger arena beyond the SEA Games and AFF Cup, adding that Vietnam needs to upgrade the football system, including giving young players more playing time.