The Football Association of Thailand (FAT) has started looking for a new coach for the U23 side as current boss Alexandre Gama is likely to quit soon.
FAT president Somyot Poompunmuang said on Monday Gama had told him a few days ago that he was in talks with a Thai League 1 club.
It is reported that the Brazilian will replace South Korean coach Yoon Jong-Hwan at struggling SCG Muang Thong United, who are at the bottom of the Thai League 1 table.
"He told us that he was in talks with a Thai League 1 club. He said he wanted to return to work at the club level," said Somyot.
The FAT boss said he would discuss the matter with Gama after he oversees the U23 team in the Merlion Cup in Singapore next month.
"We have started our search for a new coach, who could be a Thai or a foreigner,'' Somyot said.
"If he leaves, we will urgently need a new one to prepare the team for the AFC U23 Championship next year. This is an important tournament because it also serves as an Olympic qualifying round."
The AFC U23 Championship will be held in Thailand from Jan 8-26.
Gama, 51, is one of the most successful coaches in Thailand.
He coached Buriram United from 2014-2016 and guided them to win the league title twice as well as the FA Cup and League Cup.
Gama steered Chiang Rai United to two FA Cup and one League Cup titles before joining the Thai U23 team last year.
Meanwhile, Yoon apologised to Muang Thong fans after the Kirins narrowly lost 1-0 at Buriram in Thai League 1 on Sunday night.
Muang Thong did well for 80 minutes before Sasalak Haiprakhon scored the winner for the Thunder Castle.