Thailand need a win against Malaysia in Mongolia on Sunday to be assured of a ticket to the 2022 AFC U23 Asian Cup.
The match at MFF Football Centre in Ulaanbaatar kicks off at 10am, Thai time, and will be televised live on AIS Play and ONE31.
After two games, Thailand are two points behind Malaysia ahead of their final Group J match in the qualifying round.
In their first two matches, Worrawoot Srimaka's men were held to 1-1 draw by Mongolia and defeated Loas 3-0 while Malaysia beat both teams.
The Young Elephants could still qualify for the 2022 AFC Asian Cup with a draw but that would depend on result of the other Group J match between Mongolia and Laos and games in other groups.
The 11 group winners plus four best runners-up will join hosts Uzbekistan in the finals in June 2022.
Thailand will be missing two centre-backs, Wanchart Choosong and Antonio Saenjairak, who are out injured.
Wanchart got injured during Thailand's opening game against Mongolia, while Antonio suffered a knee injury against Laos.
Midfielder Benjamin Davis, who plays for English League One side Oxford United, is also doubtful.
"We will be without Antonio while some players need a late fitness test. Otherwise we are fully fit," said Worrawoot.
"Our aim is to qualify for the finals so we have to get three points."
Thailand's strike force will be led by Thanawat Suengchittawon and Jakkit Phalapol who have scored three of the team's four goals in Mongolia.
Jakkit netted one goal each against Mongolia and Laos while captain Thanawat, of English Premier League side Leicester City, was on target against Laos.
"Everybody in the team is confident," Thanawat said.
"We only think about getting three points."
He said he had watched tape of Malaysia's previous matches and believed Thailand could beat them.
"I do not feel under pressure. We have to play like we did against Laos. Everybody knows this is the most important game of this qualifying tournament and everybody will give his all," Thanawat said.
Thailand manager Nualphan Lamsam said she would give the team two million baht if they defeat Malaysia.
The Young Elephants have already got one million baht from Nualphan for their win against Laos.
It is Nualphan's first tournament after being appointed as manager of the national men's senior team and the U23 side by the Football Association of Thailand a few months ago.
