Runaway Thai League 1 leaders Buriram United aim to wrap up the title with a win at second-placed Bangkok United on Tuesday night.
After 24 games, defending champions Buriram have 64 points, 12 ahead of Bangkok United.
Buriram coach Masatada Ishii said on Monday that a number of his players played for the Thai national team during the recent international break including forward Supachai Chaided, the league's leading scorer.
"We have to focus on our players' fitness," the Japanese boss said.
"We will be champions if we get three points tomorrow [today]. Our target is to be unbeaten champions who win three trophies."
The Thunder Castle are seeking a clean sweep of the T1, League Cup and FA Cup titles for the second season in a row.
They are in the semi-finals of the Cup competitions.
Buriram will start favourites tonight as they thrashed the Angels 3-0 at True Stadium in a Cup match in February.
"We hope we win and become champions again," said Ishii.
Bangkok United coach Totchtawan Sripan said Thailand international players Manuel Tom Bihr, Thitiphan Puangchan or Peerapat Notechaiya need a late fitness test while striker Heberty Fernandes is suspended.
He said stopping Buriram from claiming the title tonight is not the main factor as he always wants his team to play for a win.
Meanwhile, Ratchaburi were held to a 1-1 draw by relegation contenders Nakhon Ratchasima on Sunday.
Jakkaphan Kaewprom gave hosts Ratchaburi a 1-0 lead after just four minutes only for Saharat Kanyaroj to equalise for the Swat Cats in the 28th minute.
Police Tero beat Nongbua Pitchaya 2-1 to send the Gamecocks closer to Thai League 2.