A few weeks ago, Buriram United were gunning for a sweep of three domestic titles but now the Thunder Castle could finish the season empty-handed.
Their failure to reach the FA Cup final was followed by defeat against PT Prachuap in the League Cup showdown on Saturday.
Buriram have also lost the outright lead in Thai League 1.
Although they are joint-leaders with Chiang Rai United with three matches remaining, fate is not in their hands.
Chiang Rai will win the title if they and Buriram end the season with the same number of points thanks to their superior head-to-head record.
Buriram need a win at Nakhon Ratchasima on Wednesday to keep alive their hopes of retaining the Thai League 1 title.
Buriram coach Bozidar Bandovic admitted yesterday that his players were still tired from the loss to Prachuap and said he would make changes to the starting line-up.
Forward Supachok Sarachat, one of the team's key players, needs a late fitness test, he said.
"I have told my players to forget the previous match and look forward to the match tomorrow [today]," said Bandovic.
"We have to win our last three games and see if that is enough."
Nakhon Ratchasima also need a result in their fight to avoid the drop.
Port, who are only two points behind the leading duo, host Chainat on Wednesday.
Chiang Rai United visit PTT Rayong on Thursday.