The 24 national U23 team probables, named by the Football Association of Thailand, started training at Bang Bo in Samut Prakan on Thursday and are scheduled to take on China in a warm-up game tomorrow. They include Worachit Kanitsribumpen, Wisarut Imura, Sittichok Paso and Shinnaphat Leeaoh.
Four national team players -- Supachai Chaided, Supachok Sarachat, Suphanat Mueanta and Ekanit Panya -- will join the squad after the War Elephants' 2022 World Cup Group G qualifier at Vietnam on Nov 19.
Thailand coach Akira Nishino oversaw Thursday's training session.
Totchtawan said the main emphasis at the training camp will be on fitness.
"The football competition of the SEA Games is very taxing for the players because many matches are played in a short period of time," said Totchtawan.
"I played in the SEA Games and I know it could be very tough for some players.
"They carry the hopes of the entire nation and it all depends on how well they can handle the pressure.
"The players have to be ready both physically and mentally. I will try to advise them and keep them motivated."
Totchtawan has been appointed as the assistant coach of the U23 squad in place of Issara Sritaro, who is looking after the Thai U19 side playing in the AFC U19 Championship in Cambodia.
Tomorrow's warm-up against China at BG Pathum United stadium will be followed by another friendly with Myanmar on Nov 13 at Chulalongkorn stadium.
Both matches will be televised live by PPTV HD (36).
Thailand are in Group B with Vietnam, Indonesia, Singapore, Laos and Brunei.
The Philippines, Malaysia, Myanmar, Cambodia and Timor Leste are in Group A.