At an online AFF conference on June 11 the Vietnam Football Federation suggested the event should be played in just one or two countries if the Covid-19 pandemic is not controlled across the region by the end of this year.
In Vietnam, the outbreak has been controlled and there has been no community transmission for over two months, making it a favorite to be host or joint host if its proposal had been accepted. Vietnam is also the defending champion.
But the AFF, after considering the suggestion, decided not to change the format, and teams will play each other at home and away just like the 2018 edition.
It said the 2022 World Cup qualifiers will also take place at the end of this year with their format unchanged, which is playing home and away matches, so it would be unreasonable for AFF to change the format of their event.
But squads can have 30 players instead of the usual 23, and teams can have 23 players for a game instead of 20 to facilitate teams' preparations after a long pandemic break.
The draw for the tournament has been postponed from June to August.