Out-of-sorts Port will try to stop the rot when they travel to bitter rivals Muang Thong United in Thai League 1 on Tuesday.
Second-placed Port could only manage a scoreless home draw with lowly Trat at the weekend, which followed three consecutive losses.
During that spell, they also were knocked out in the defence of their FA Cup title.
Fourth-ranked Muang Thong, meanwhile, have enjoyed an impressive run and won 3-1 at Ratchaburi at the weekend with Sardor Mirzaev scoring a hat-trick.
Port coach Sarawut Treephan said yesterday the team needed to regain confidence.
"The situation in the team is still okay but we must find a way to score," he told a pre-match press conference.
"We -- the players and coaches -- have to help each other. We need a result today to bring back our confidence.
"Muang Thong have a good counter-attacking game and we must be careful about this."
Earlier, Sarawut complained about the refereeing in certain matches but said he was ready to take responsibility for the team's bad results.
Port, who are 16 points behind leaders BG Pathum United, must finish second this season to earn a berth in the AFC Champions League group stage in 2022.
The third-placed side will have to compete in the play-offs along with the FA Cup champions.
The Kirins coach Mario Gjurovski said: "I think Port are favourites in this game. Although we are at home, there are no spectators. So we won't have a home-field advantage.
"Port are second and have many good players. However, we want to continue winning after beating Ratchaburi."
Buriram United host champions Chiang Rai in tomorrow's big match.
Buriram are at full strength without any injured or suspended players, said manager Boriphan Soonrod.
He said his defenders must keep a close eye on Chiang Rai striker Bill Rosimar who scored twice in his team's 3-2 win over Rayong on Sunday.
Chiang Rai manager Prat Malarat said his players' confidence was boosted by the win against Rayong after a string of poor results.