Sirirak first task will be helping Nishino in the FIFA World Cup 2022 Qualifiers in which ‘Changsuek’ starts their campaign against Vietnam at home on Sept 5.
FAT chairman Somyot Poompunmuang had a meeting with Nishino, Sirisak and Anurak on Tuesday.
Sirirak stepped down as the national head coach a few months ago, while former Thailand international Anurak has coached several clubs as well as the country's U19 team.
Somyot said Nishino picked Sirisak and Anurak from a list prepared by the FAT. He said the FAT was looking for two more coaches to help Nishino who must not be under contract with any club.
Japan's Nishino, who guided his country to the knockout stage at the 2018 World Cup, takes over both Thailand's senior and U23 teams.
After Nishino gets four assistants, the Japanese, FAT officials and parties concerned will discuss who would help him with the senior and the U23 sides, Somyot said.
"There are many coaches who are interested in the job. Unfortunately, they already have jobs at clubs," Somyot said.
FAT president said that SCG Muang Thong United coach Totchtawan Sripan didn’t in the staff list as he wanted to take care of his new-born baby.
"Coach Ban [Totchatawan] is good and is unemployed, but he can't start working immediately. However, he could be considered in the future," Somyot said.
After Vietnam, Thailand will travel to Indonesia on Sept 10 for their second World Cup qualifier.
Winners of the eight groups and four best second-placed sides will make it to the third and final stage of the Asia's World Cup qualifiers.
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