The Thai men's U23 team face a tough assignment in the defence of their SEA Games title following Tuesday's draw in Manila for the 2019 tournament.
Thailand are in Group B with Vietnam, Indonesia, Singapore, Laos and Brunei.
Hosts Philippines, Malaysia, Myanmar, Cambodia and Timor Leste are in Group A.
The 2019 SEA Games begin on Nov 30 but the men's football tournament kicks off on Nov 25.
Thailand are favourites to retain the title as they are likely to have several young players who have already played for the senior national side, including Supachai Chaided, Supachok Sarachat, Supanat Mueanta and Ekanit Panya.
The men's football tournament at the SEA Games is a U23 competition. Thailand are coached by Akira Nishino, who also handles the senior national team.
Former Thailand U23 coach Worawoot Srimaka, who guided Thailand to the 2017 title, said the draw was not too difficult for Thailand.
He said Thailand and Vietnam would compete for the top spot in the group.
The top two teams of each group advance to the semi-finals.
In the draw for the women's football event, Thailand are in Group B with Vietnam and Indonesia.
The Philippines, Myanmar and Malaysia are in Group A.