Northern Ireland manager Lawrie Sanchez was stunned by his side's second-half collapse against England in the World Cup qualifier at Old Trafford.
"It is strange because we played so well defensively in the first half and within nine minutes we had given them three goals," said Sanchez.
"Obviously the first goal was a major one, giving it away so early.
"But that did not finish the game for us, it was the way we reacted. Our heads were down and we conceded three."
Sanchez admitted Northern Ireland had to get a result against Poland on Wednesday to keep even slim chances of progress alive.
He will have to do without Birmingham midfielder Damien Johnson, who was booked for kicking the ball away and is suspended for the game in Warsaw.
"We can't afford to lose a player for kicking the ball away," said Sanchez.
"We are a small nation with a small group of players and we can ill-afford to lose players through suspension.
"If we lose on Wednesday the group is over for everybody but England and Poland. I certainly want to be able go to Belfast when England revisit us for the first time in 20-odd years with a chance. There is a lot of work to be done."