Despite their 3-2 victory over Myanmar in a warm-up game on Wednesday night, Thai U23 team assistant coach Totchtawan Sripan insists his men "need to improve a lot of things" before the SEA Games.
The win helped Thailand make amends for their 2-1 loss to China U23 in another warm-up game last week as they prepare for the regional sports festival in the Philippines later this month.
The Thais saw Anon Amornlertsak net twice and Jaroensak Wongkorn convert a penalty for their third goal at Chulalongkorn Stadium on Wednesday night.
Totchtawan is also worried about the risks involved in training on an artificial surface for too long.
"It may make our team get used to the pitch but we don't know whether the surface in the Philippines will be the same as here or not. The players can get injured easily," said the former Thailand international.
"The combination between the players is still not good enough, but it is something that [coach Akira] Nishino will take care of when he takes over."
"Our performance against both China and Myanmar wasn't smooth but don't forget that we have four key players away with the national team for the 2022 World Cup qualifiers," Totchtawan added, referring to Supachai Chaided, Supachok Sarachat, Suphanat Mueanta and Ekanit Panya.
The War Elephants played their fourth Group G game of the Asian zone qualifiers for Qatar 2022 at Malaysia late last night and will next take on Vietnam in another away game on Tuesday.