Coach Akira Nishino aims to steer Thailand to Asia's final qualifying round for the 2022 World Cup by winning the three remaining matches.
The War Elephants arrived home on Wednesday after a scoreless draw with Vietnam in Hanoi on Tuesday night.
With the result, Vietnam remain leaders of Group G of Asia's second qualifying stage for the Qatar World Cup.
The Vietnamese have 11 points from five matches while Thailand dropped to third with eight points, one behind Malaysia who beat Indonesia 2-0 in Kuala Lumpur in the group's other match on the same day.
Having also played to a 0-0 draw in their first meeting in September, the all-Southeast Asian tie in Hanoi was as captivating as expected.
While the Golden Dragons dominated for long periods, Thailand created more scoring chances.
The War Elephants' best chance came in the 27th minute when Vietnam's Doan Van Hau was penalised for bringing down Thailand defender Manuel Tom Bihr.
Theerathon Bunmathan took the spot-kick, but Vietnam goalkeeper Dang Van Lam, who plays for Thai club Muang Thong United, pulled off a spectacular save to send the fans at the My Dinh Stadium into delirium.
With the eight group winners and four best runners-up progressing to the continent's 12-team final qualifying stage for the 2022 World Cup, Thailand have a mountain to climb to reach the next round.
"There are still three matches to play. We still have a chance to advance but we must keep fighting,'' Japanese Nishino said yesterday.
"We must try to win all the three remaining matches. Before our next game [against Indonesia] in March, we will look for new players to make us stronger.
"The game against Vietnam was tough as they were playing at home. They are leaders of the group so they did not have to try hard to score against us.
"They could play defensively. We tried to score but we could not score. Our players did their best."
Theerathon said every player tried very hard but it was his fault that he missed the penalty that cost Thailand a win.
In their last three games, Thailand host Indonesia on March 26, travel to the UAE on June 4 and are at home against Malaysia on June 9.