The absence of tennis ace Do Minh Quan at the Davis Cup, on Wednesday, led to three consecutive losses to the event's hosts, on June 15.
Speaking to Thanh Nien from Sri Lanka, Coach Nguyen Dinh Bao Tri said the coaching staff was letting Quan rest because he had a cold.
However, doubts remain about the situation, especially after Quan got into a dispute with Coach Truong Quoc Bao a couple of days before the competition.
Le Quoc Khanh played the first match against Sri Lanka and lost 2-6, 3-6 to Oshada Wijemanne.
Then, Hoang Thanh Trung lost 1-6, 4-6 to Harshana in the second match before the duo Quoc Khanh and Quang Huy lost 1-6, 7-6, 5-7 to the Sri Lankan pair Harshana/Hangarajah.
The losses made it extremely difficult for Vietnam to fight for the top two places of the group.
The Vietnamese tennis players will next clash with Kuwait and Myanmar in the hope of remaining in the third group rather than being relegated to group four.