Thailand begin the defence of their Asean title against Brunei in Kuala Lumpur today.
In today's other Group A match, Cambodia meet the Philippines at Phnom Penh with Indonesia being the other side in the pool.
In Group B of the biennial Southeast Asian championship are Vietnam, Malaysia, Myanmar, Singapore and Laos.
The top two teams in each group advance to the semi-finals.
While Brunei are ranked outsiders, Thailand coach Mano Polking said he won't underestimate any opponents in the tournament which is officially known as the Mitsubishi Electric Cup.
"We are the defending champions and of course we want to start with three points," Polking told a press conference yesterday.
"But we have to respect our opponents and cannot underestimate any teams in our group. We must concentrate on what we have to do.
"This edition is different from to the previous one [which Thailand won earlier this year]. We have had two weeks to prepare for the tournament which is good.
"Our preparations are good and I have seen several things in our players. They work hard and want to be in the starting line-up. We have several new players and I am ready to give them chances to play."
The War Elephants had two warm-up games, whipping Myanmar 6-0 and losing 1-0 to Taiwan.
Polking said he was not bothered by the results of the friendlies.
The German-Brazilian tactician said he used the two games to test his tactics and new players.
"Although the result of the previous match [against Taiwan] was not what we had expected, it helped us ready for the tournament," he said.
As one of the weakest sides in the region, Brunei, coached by Spaniard Mario Rivera, had to play in a home-and-away play-off for a place in the 10-team tournament.
Polking, 46, said he saw Brunei's fighting spirit in their play-off win against Timor Leste.
"On paper, they are seen as the weakest team in the group but that means nothing on the pitch," he said.
Polking became a national hero when he guided the War Elephants to regain the Asean crown in his first assignment as coach of Thailand.
But Thailand have since failed to shine and could only finish third at the King's Cup in Chiang Mai where they lost to Southeast Asian rivals Malaysia.
He will feel the pressure as he probably needs another triumph in the regional championship to save his job as coach of Thailand.