Centre-back Do Duy Manh will miss King's Cup 2019 due to injuries. Photo by VnExpress/Anh Khoa

Under coach Park Hang-seo, Vietnam became a hard-to-beat team with a solid defense, propelling them to outstanding results, including the AFF Cup 2018 victory and a top eight finish at the Asian Cup 2019.

Throughout the AFF Cup 2018 campaign, Vietnam’s centre-back trio of Tran Dinh Trong, Do Duy Manh and Que Ngoc Hai was a sturdy fence in front of the goalkeeper. Together, they struck a good balance between experience, strength and skills.

However, after the Asian Cup 2019 concluded, each struggled to recreate their excellent form for their clubs.

Que Ngoc Hai, the captain of the national team, was suspended more often than he played for committing dangerous fouls and injuring other players.

Que Ngoc Hai was captain of Vietnam national football team at the Asian Cup 2019. Photo courtesy of Asian Football Confederation

In the first game of V. League 1 2019, he got a red card and missed the second game.

Hai was then suspended four games in March after stepping on the shin bone of Hanoi FC’s Tran Van Kien, badly injuring him.

In nine matches, Hai only made four appearances for Viettel FC and the team didn’t win any of those games, losing three and drawing one. His calmness and accuracy was not in evidence, instead there was lack of concentration and hot-headed decisions.

Tran Dinh Trong has also struggled to find his form after going in for surgery to treat an injury after the AFF Cup 2018, in which he performed excellently and contributed to Vietnam’s victory. He became noted for an intelligent playing style and the ability to read the game.

Tran Dinh Trong (L) in the AFF Cup final match against Malaysia on December 15, 2018. Photo by VnExpress/Duc Dong

But in the last couple of matches, he has put in disappointing performances, with Hanoi conceding six goals in the two matches that he started for the club, especially a shocking 1-4 defeat to Thanh Hoa FC when he received a red card for a rough play.

Trong’s teammate at Hanoi FC and the Vietnamese national team, Do Duy Manh, has performed well but was unfortunately sustained an injury that will take at least three weeks to recover.

At a press conference on May 14, Hanoi FC coach Chu Dinh Nghiem confirmed Manh’s injury.

"After undergoing tests, Duy Manh was diagnosed with a scraping, bone marrow edema and calf bone issue. He needs at least three weeks to recover."

So Manh will most certainly miss King’s Cup 2019, a friendly but important tournament for Vietnam because its results will affect Vietnam’s FIFA rankings.

A possible replacement for Manh is Viettel FC’s Bui Tien Dung, who played well at the Asian Cup 2019. But just like his club mate Hai, Dung has underperformed, leading to Viettel’s recent downfall.

Bui Tien Dung steps up to take a penalty in the game between Vietnam and Jordan in the Asian Cup round of 16 on January 20, 2019. He scored the goal. Photo by VnExpress/Anh Khoa

With the main defense pillars out of form, coach Park has a headache. He must find a way to readjust and find some replacements for the defense line.

The King’s Cup will take place early next month in Thailand. Vietnam will face hosts Thailand on June 5 while India face Curaçao the same day.

The winners of these matches will meet in the final on June 8, while the two eliminated teams will play a third place playoff match the same day. All four matches will take place in the northeastern province of Buriram in Thailand.