England Under-21 manager Aidy Boothroyd believes it is not possible to succeed in the role, as his side face a second successive group-stage exit from the European Championship.
"The England senior men's job was called the impossible job," he said.
"The England U21 team is the utterly impossible job."
Former Watford manager Boothroyd has led England Under-21s since 2016.
Boothroyd's side won the Toulon Tournament in 2018 but exited the last European Championship in 2019 at the group stage without winning a game. England have not won the Under-21 Euros since 1984.
Boothroyd said the way the England international set-up is structured limits the chances of the under-21s winning tournaments.
"It's not possible to win at all levels," Boothroyd said.
"Part of the reason we haven't won this for 37 years is [that the under-21s' role is] to get players to the first team."
Former England defender Micah Richards said Boothroyd has to be judged on the under-21s "winning things" and questioned England's mentality towards the team.
Boothroyd said he thinks he has done a "successful job" and revealed he has been in regular contact with senior boss Gareth Southgate while Football Association technical director John McDermott is in Slovenia with the side.
"Are we on the same page? Absolutely. All the way through the pathway, we're on the same page," said Boothroyd.
"You shouldn't be working in youth development if you think your job is to win every game and not produce players for the senior team.
"We have won things in the younger age groups and as they've matured, they've been fast-tracked. That's how it works. That is the way to do it."
Asked if Wednesday's game is the biggest of his career, Boothroyd replied: "I think it is - it's about keeping a cool head now."
They will be without Callum Hudson-Odoi, who has returned to Chelsea with an injury, while Arsenal midfielder Emile Smith Rowe is a doubt.
'The only team that needs to win is the senior team'
Fourteen players who represented England in the 2017 and 2019 tournaments have since featured for the full international side, including Mason Mount, who has played in England's past seven games, and Phil Foden.
Boothroyd said he was "hoping" to have Mount at the tournament, along with Borussia Dortmund midfielder Jude Bellingham, who is also with Southgate's full squad.
"Could you imagine a reserve-team manager going to a first-team manager and asking to have their best player to win the reserve-team championship?" asked Boothroyd. "That wouldn't happen.
"The only team that needs to win is the senior team. The main thing is the senior team, everyone is here to support the senior team."
Speaking in his news conference before Wednesday's 2022 World Cup qualifier against Poland, Southgate said balancing the squads is "difficult".
"Nobody thinks about the U21s from outside until you get to the finals," Southgate added.
"I think it's always a good question - we want to try to win tournaments when we can. We have benefited when the under-17s won and also the under-20s."
'Boothroyd has to be judged on winning things'
Former England and Manchester City defender Micah Richards, who played 15 times for the Young Lions, said the way the under-21 team is seen in England is "totally wrong".
"We think once we get to seniors we are too good for the 21s," he told the BBC's Monday Night Club.
Richards pointed to the 2009 Under-21 Euros final where he was part of an England side who lost 4-0 to Germany.
The Germany squad included Manuel Neuer, Jerome Boateng, Mats Hummels, Sami Khedira and Mesut Ozil, who were all part of the Germany team who won the senior World Cup five years later.
"They wanted to win, then what happens? Some of those players go on to win elite trophies - because it is embedded in them from a younger age to win," Richards said.
"Boothroyd has got to be judged on them winning things, not on who he produces.
"If you win things you're developing players, you are developing winners.
"When you are under-15 or under-16 that is development. At under-21s the next step is seniors. You need to have that winning mentality."
Nicky Butt to replace Boothroyd?
BBC Sport's Simon Stone:
Aidy Boothroyd's contract is due to expire in the summer.
It is hard to see how the deal will be extended if, as expected, England crash out at the group stage for the second season running.
As England are not scheduled to have another game until September if they do miss the knockout stages, the FA do have time to think about replacements.
One name that has been mentioned is Nicky Butt.
The former Manchester United midfielder has extensive experience working with the various age group teams at Old Trafford and having left the club in the wake of the reshuffle that saw Darren Fletcher named technical director and John Murtough's powerful position reinforced with the football director title, Butt is available.
In addition, Butt is known to be interested in front-line management.
However, current England Under-20s boss Lee Carsley and his assistant Jason Euell have their admirers also and are bound to be in contention.
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