Coach Kiatisak Senamuang has signed a two-year contract with his former Vietnamese club Hoang Anh Gia Lai, the ex-Thailand boss said on Monday.
Kiatisak, who previously played for and coached the Vietnamese team, revealed the move on social media.
"I have not spoken Vietnamese for some 17-18 years so I may not be fluent," Kiatisak, speaking in both Vietnamese and English, said in the post.
The 47-year-old said he chose to work with the team after club owner and president Doan Nguyen Duc asked him to return to help the team.
"I told him 'okay' immediately. I always think that he gave me chances to be the team's player and coach so there was no reason to turn down his offer," said the former Thailand striker, who is affectionately called 'Zico' by Thai fans and journalists.
"In fact, they are a rich club owned by a billionaire and can choose anyone. But he sees me as an important figure and believes in my skills."
Doan said last season Hoang Anh Gia Lai played entertaining football but could not score many goals.
"Our players lacked motivation. I need someone who can do the job and that person is Kiatisak. Some of our players see him as an idol and like his stlye," he said.
"That is why I asked him to come back to Vietnam."
Kiatisak, who will begin his latest job in the 2021 season, played for Hoang Anh Gia Lai from 2002-2006 and helped the club win the V-League twice in 2003 and 2004.
He later became coach of the team with little success.
He will reportedly receive US$26,000 (787,000 baht) a month.
Kiatisak will go to Vietnam early next month and will have to enter state quarantine for 14 days before starting his work with the club on Dec 17.