Thailand national football team on Tuesday reported for a training camp to prepare for their two Fifa Day friendlies with Taiwan and Hong Kong.
A total of 20 players joined the camp for the games with Taiwan on June 16 and Hong Kong three days later.
Three foreign based players -- Elias Dolah, Chanathip Songkrasin and Supachoke Sarachart -- will join the team on June 13.
Thailand coach Mano Polking said his prime concern is the level of fitness of different players.
"This time we are having a training camp when no domestic league matches are being played," he said.
"This means that some of the players have been playing a lot of football while others haven't seen much activity at all.
"Our main task will be to bring every player to the desired fitness level as soon as possible."
Thailand players attend a training session on Tuesday.
Polking added that he had decided to invite four players from the 2023 SEA Games team to join the senior squad.
"I hope that Channarong Promsrikaew, Teerasak Phoephimai, Chatmongkol Ruangtanaroj and Anan Yodsangwan will make the most of this opportunity."
On matches against Taiwan and Hong Kong, Polking said: "When planning such friendlies, we need to strike a balance.
"This time we have opted to play against two lower ranked teams because we have some tough games scheduled for October when we will be visiting Europe."
The War Elephants will depart for Taiwan on June 14.