Imam-ul-Haq says Pakistan will go all out against Bangladesh on Friday despite their chances of reaching the semi-finals being remote.
England's win over New Zealand on Wednesday meant the best Pakistan can now do is finish level on points with fourth-placed New Zealand on 11 points.
But their run rate is inferior to New Zealand's and they need a record-breaking win at Lord's on Friday to take fourth.
They must bat first, if they field they will not be able to overhaul the Black Caps regardless of what they do, and they must triumph by a margin of 316 runs or more.
To put that task in context, the record for biggest winning margin at a World Cup match is 275, achieved by Australia against Afghanistan in 2015.
Speaking before England had won, Imam said there was no despondency in the Pakistan camp despite the difficult situation that they were facing.
"We are not thinking on the lines of not reaching semi-finals," said Imam. "Our plan is to play the semi-final with an all-out effort and at the end if that doesn't happen then we have to play positive cricket and end on a high."
Pakistan won just one of their first five World Cup matches but bounced back strongly with victories against South Africa, New Zealand and Afghanistan to give themselves a shot at reaching the semi-finals.
But England's return to form has scuppered things somewhat and Pakistan have been left to reflect on where they have fallen short.
Imam said the 41-run defeat against defending champions Australia earlier in the competition was painful.
"I think the Australia defeat hurts me a lot. I was set and playing well. I should have won that match for Pakistan," said Imam.
"We lost four quick wickets and I think I should have won that game and we would have beaten a big team in the World Cup."
Imam, who scored his only fifty of the tournament in that match, said he was disappointed with his batting during the tournament.
"I think what expectations I had from myself I could not do like that," said Imam, who has so far scored 205 in seven innings. "I had starts but couldn't score big.
"I am very young so I have learned a lot in this World Cup. What mistakes I have committed, I have learned from them and I am sure that will help me," said the 23-year-old.
Meanwhile, police have launched an investigation after the "unprecedented" crowd trouble at the match between Pakistan and Afghanistan at Headingley last Saturday, during which a number of arrests were made.
West Yorkshire Police said they received reports of people climbing over a wall, assaulting staff on a gate and a fan going on to the pitch at the game in Leeds.
Videos shared on social media show a fight between fans outside the ground, with a metal barrier being brandished and kicks, punches and shouting.
Police said mobile phone footage showed people being assaulted, and appealed for anyone who was a victim or witness of an attack, or who has original footage of the incidents, to contact them.
Superintendent Chris Bowen said police in Leeds recognised the need for a "full and comprehensive criminal investigation".
"While these were isolated incidents, involving a relative minority of people attending the event, the scenes that were witnessed were completely unprecedented at a cricket match," he said.
"While we did not receive any direct reports of people being injured, the footage that is out there clearly shows people being assaulted during these incidents," he added.