Midfielder Eugen Polanski says Poland will show no mercy to the Czech Republic when the two sides meet in an all or nothing Euro 2012 Group A decider on Saturday.
Poland must win to reach the knock-out rounds for the first time in their history in the European Championships while the Czechs know that anything other than a win could see them eliminated.
A draw might be enough for the Czechs, unless Greece beat Russia, whereas for Poland it's win or bust.
And Polanski promised a frantic effort from his team-mates.
"We know we have to win but it's not a case of whether or not that's an advantage, we simply have this message in our heads," said the Mainz 05 midfielder.
"From the first minute we have to kick their arses. I'm sorry to use this expression but that's how it works.
"If we play like we did against Russia then we'll have no problems."
Although Poland have twice reached the World Cup semi-finals and won the Olympic Games in 1972, their Euro record is poor.
Four years ago they reached the finals for the first time but they headed into a cul-de-sac and failed to win a game, crashing out of the group stages.
Victory over the Czechs would give Poland a first win in the competition as well as a first progression to the knock-out rounds.
"We know this is an extremely important match, it's a historic match," said Polanski.
"If we win we could do something special for our fans and for the country but we have to focus on the game and nothing else for 90 minutes.
"For me it's definitely the most important match in my career but the whole tournament is important.
"We're very focussed, we have to prove that we're prepared. We've trained hard for five weeks and we want to demonstrate that we can give everything because if we give 100 percent, we'll definitely win."
Coach Franciszek Smuda is planning a different therapy to his player and says he wants everyone to remain calm.
Smuda admitted he had been nervous before the opening match against Greece but said now he's got a hold of himself.
"For me each game is extremely important but this is probably the most important one in my life but also for the whole team," he said.
"We simply have to remain calm. We definitely don't feel this great pressure. The players feel pressure but not as much as before the Greece match.
"Before that one I admit I felt it."
Smuda said he would probably pick the same team that ran out onto the pitch against Russia, as long as he doesn't have any injury problems that prevent him from doing so.
Polanski, fellow midfielder Dariusz Dudka and defender Damien Perquis were all struggling with knocks after the Russia game.
But even if one or more of those doesn't make it, Smuda says of more importance is attacking at speed.
"It's not important who plays, the important thing is to react quickly and counter quickly because this is how teams play now," said Smuda.
"The most important thing is to be 100 percent focused and to not make silly mistakes. You can't avoid making mistakes because this is football but you must make as few as possible."