Thailand coach Salvador Garcia said on Tuesday his men cannot underestimate Laos when they meet in the semi-finals of the AFF U19 Championship in Jakarta on Wednesday.
In the other last-four match, Vietnam take on Malaysia.
Thailand were Group A runners-up while Laos topped Group B.
"It will not be an easy game but I hope our players do well," Garcia told a press conference.
"We cannot underestimate them. Although we have more football resources, this is a one-off match and anything can happen. I believe Laos are ready to create problems for us.
"They have clear tactics and also have many talented players. Their players work very hard. It will be a difficult game for us but we will try to get past them."
The Spaniard said his team, who scored only seven goals in five matches in the group stage, need to improve their attacks.
"We did not score many goals in the group stage. On the other hand, we conceded only one goal, which is good. But there are many areas that we have to improve. We must do better in our attacking game."
He said he has faced Laos twice but the current squad is a different one.
"They are different teams but the coach is still the same -- Michael Wise," Garcia said.
Meanwhile, less than five months before the World Cup, Iran sacked national team coach Dragan Skocic on Monday, the official Irna agency said.
Croatia's Skocic, 53, was appointed in February 2020 to replace Belgian Marc Wilmots, who left in December 2019, three matches into the second round of Asia's World Cup qualifying, after two consecutive defeats.
Skocic guided Iran to their sixth World Cup. He won 15 of his 18 games in charge.