Without a win in their three warm-up matches, Thailand coach Akira Nishino admitted that his men must lift their game when they face Indonesia in a World Cup qualifier on Thursday.
The Thais lost 4-1 to Uzbekistan in their third and final warm-up game in the United Arab Emirates on Sunday night, having lost 1-0 to Oman and drawn 2-2 with Tajikistan earlier.
Adisak Kraisorn gave Thailand the lead early on only for Uzbekistan to hit back with four unanswered goals in a match of three 30-minute periods.
"We used several players for the games against Tajikistan and Uzbekistan," Nishino said.
"We wanted to try our players and to select the best squad for the World Cup qualifiers."
He said his men did not have many chances to enter the scoring zone in the game against Tajikistan although they scored twice.
He then changed the tactics against Uzbekistan and his players had more scoring chances although they conceded four goals.
The Japanese coach admitted that his players were not yet fully fit.
"For the game against Indonesia, we have to lift our game to a higher level," Nishino said.
The War Elephants are preparing for their remaining three Group G matches of Asia's second qualifying stage for the 2022 World Cup.
They will meet Indonesia on June 3, the UAE on June 7 and Malaysia on June 15. All games will take place in the UAE and kick off at 11.45pm, Thai time.
With the top eight group winners and four best runners-up advancing to the next round, the War Elephants have a slim chance of reaching Asia's third and final qualifying stage.
After five games, Vietnam lead the group with 11 points, followed by Malaysia (nine) and Thailand (eight).
The UAE have six points from four games while Indonesia have yet to claim a point.