The Croatian Football Federation has informed the FAT that it will not send a team to take part in the four-team tournament to be held in Nakhon Ratchasima from Feb 1-7.
The other two teams in the tournament are South Korea and North Korea.
"We have contacted Malaysia, South Africa and Uzbekistan," said FAT president Worawi Makudi.
"It is likely to be Malaysia who may use the team which finished second in the AFF Suzuki Cup."
Malaysia lost to Thailand in last month's AFF Suzuki Cup final.
Thailand coach Kiatisak Senamuang earlier said a rematch with Malaysia would be interesting but he preferred a Middle East side.
Thailand could meet teams from that region in the 2018 World Cup qualifying which begins this year. Bangkok Post