After returning to Hanoi Friday night following a heavy loss to Australia, the national team, including Hai, underwent rapid antigen tests. Hai's result returned positive.
There’s a possibility that the 29-year-old defender had contracted the virus from Lieu Quang Vinh, who was confirmed positive a few days ago.
Hai had missed the Australia match because of a suspension.
On Saturday morning, the national team had their samples taken for PCR testing. If Hai is confirmed infected with Covid, he would have to be quarantined, meaning he would not be able to join the match with China at the My Dinh Stadium in Hanoi on the first day of the Year of the Tiger.
Hai's absence would significantly affect the calculations of Coach Park Hang-seo. Except for the match against Australia, the centerback from Nghe An Province is one of the two rare players to fully play the previous six matches in the third qualifying round.
After seven defeats, Vietnam are at the bottom of Group B.
Hanoi authorities had earlier approved a proposal to welcome 20,000 fans to the My Dinh National Stadium for the February 1 clash.