The Korean has been under fire after Thai athlete Rungravee Khurasa claimed that the coach attacked her after she crashed out in the first round at last week’s Korean Open.
In an interview on TV Channel 3 on Wednesday, Rungravee claimed Choi hit her face once and then landed several punches on her body.
Thai officials have set up a committee, led by Surawut Maharom, to look into the matter.
Taekwondo Association of Thailand (TAT) president Pimol Srivikorn said Wednesday Choi, who is still in South Korea, felt under pressure. On Thursday morning, he confirmed that the South Korean coach would not return to Thailand as planned.
"I called him and gave him moral support. He told me he felt sorry," said Pimol.
"He said he always did his best for the team but unfortunately got bad things in return. He is unsure if he will return to Thailand."
TAT official Preecha Tortrakul, who brought Choi to Thailand in 2002, said it would be a huge loss for Thailand if Choi quit as coach of the national team after a brilliant spell.
Thai athletes are in their final training stages for next month’s Youth Olympics and the Asian Games in September and they would be affected by Choi’s departure, Preecha said.
The TAT does not have a formal contract with Choi who receives 200,000 baht a month from the TAT, he said.
"We only have a gentlemen’s agreement. He could be lured by a lucrative offer from another country," Preecha said.
"But he loves Thailand and Thais love him."
Choi arrived in Thailand just before the 2002 Asian Games in Busan, South Korea, and guided Yaowapa Burapolchai to win a silver at the tournament.
Under the coach, Yaowapa became Thailand’s first ever Olympic medallist in taekwondo at the 2004 Athens Games.
Thailand have since become contenders in major international events including the Olympics.
Butree Puedpong won a silver at the 2008 Olympics and Chanatip Sonkham got a bronze at the 2012 London Games.
Yaowapa said Wednesday the athlete should know why she was punished by the coach.
"He always wants his athletes to do better," she said.