Teenage star Suphanat Mueanta hopes Thailand will be ready for next month's World Cup qualifiers as the national side's preparation has been rocked by Covid-19 cases.
The 18-year-old forward is one of the second group of players who started training yesterday at Buriram Football Training Camp in Samut Prakan.
The first group is self-isolating at another camp after some players and officials initially tested positive for Covid-19 although they all were negative in further tests.
Suphanat said every player must get ready for the matches which will be played in the United Arab Emirates.
"I am trying to regain fitness," the Buriram United player said.
"Every player must do their best and get ready before we leave for the UAE."
The Thais are preparing for their remaining three Group G matches of Asia's second qualifying stage for the 2022 World Cup.
The War Elephants will play against Indonesia on June 3, the UAE on June 7 and Malaysia on June 15.
With the top eight group winners and four best runners-up advancing to the next round, the War Elephants have a slim chance of reaching Asia's third and final qualifying stage.
After five games, Vietnam lead the group with 11 points, followed by Malaysia (nine) and Thailand (eight).
The UAE have six points from four games while Indonesia have no points.
Meanwhile, the Thai futsal team beat the hosts UAE 1-0 in a warm-up match on Sunday.
Thailand coach Jose Maria Mendes said his men have to improve their finishing as they had 26 shots but could only score one goal.
Thailand will face Iraq in a two-leg play-off in the UAE on May 20 and 25 with the winners qualifying for the Fifa Futsal World Cup in Lithuania in September.