Jurgen Klopp knows it and, as he himself admits, Pep Guardiola knows it too.
The Manchester City manager was basking in the glow of his club’s first win at Anfield for 18 years in February when he felt prompted to make a pertinent observation about the 4-1 win.
“Hopefully next time we can do it with a similar performance with the spectators as Anfield with and without fans is completely different,” said the City manager.
He was right, of course.
As Alisson Becker’s costly mistakes helped condemn Klopp’s team to a third straight home setback at the time, Anfield, one of the most famous cauldrons in world football, was Anfield in name only.
With no fans to inspire a team stricken by injury and weakened by confidence, Liverpool He would work up to three more consecutive losses at home to bring up the record for the most unwanted club.
Having spent nearly four years with a loss at home in the Premier League, they lost half a dozen between late January and early March for the first time in 129 years of history.
It is unthinkable to believe that Mohamed Salah’s 63rd-minute draw from the penalty spot would not have been the spark the Kop needed to wake up the troops on that cold February afternoon, if 54,000 had been inside.
Instead, the leveler was greeted with a quiet celebration from the home dugout before City rioted in the final third of the game.
Sunday sees the return of Guardiola’s men to Merseyside as once again the two most recent Premier League champions. go head to head inside a crowded soccer stadium.
“I am happy that Anfield is full again, it is good that they come back and we can enjoy a fantastic atmosphere and I hope we can handle it in a good way,” Guardiola said when questioned on Friday.
The city chief, however, is well aware of the impact that those on the terraces can have on his side, particularly when his team’s bus reaches the red half of L4.
He added: “I’m sure the players enjoy playing with the fans at Anfield more than without them.
“We didn’t win at Anfield, and I don’t know the reasons, like in the last four or five years because they are an exceptional team.
“The crowd helps, like in Paris [on Tuesday] , but it happens in big stadiums.
“In Germany in Dortmund or Atlético de Madrid. It happens, it is not much because of intimidation, but because of the quality of the rival. We play our game with or without spectators.”
Guardiola can insist that City’s game plan remains unchanged regardless, but there is little evidence to the contrary that Anfield, in full bloom, intimidates their expensive squad.
In Klopp’s seven games against Guardiola in all home competitions, his team won five of them, with their only loss in that game 4-1 earlier this year.
Rarely have City been able to resist when the tempo and volume are up to 11.
Is what hands Klopp extra ammo for Sunday’s blockbuster event as it welcomes the champions at a time when their free-scoring attackers are backed – apart from Brentford – by a petty defense.
“Two years ago, I said we needed that environment where even the guys who sell hot dogs need to be vigilant!” Klopp said Friday.
“We need that again. I know we go a long time without each other and I don’t have to ask again. People have been exceptional since they got back.
“I’ve loved every second, but everyone at the stadium on Sunday knows that it only makes sense when we do it all together.
“And I’d really like to say that we should all try together and be as powerful as we can.
“I know, everyone knows, we need him. We have a better chance with him, so let’s make it a really special game and yeah, it’s obvious there is a big difference with and without, so let’s set a new level for that. “
City were by far the best team in the country last time out, claiming the Premier League title by 12 points.
But that empty and soulless shell of a campaign has been consigned in the deepest corners of the mind as far as it goes. Klopp and company as worried now.
Like city of Guardiola ride on sunday afternoon, your task is to show that, in fact, they can withstand the heat in the kitchen when the red-hot atmosphere inevitably rises.
For Liverpool, his own challenge is to rise again to the level of excellence necessary to beat the champions.
It may not be the two-horse race of previous years, but Sunday could still have a major influence on the fate of the title in May.
And both managers know it.