Manchester United's interim manager Ralf Rangnick said his club, beaten 4-0 at Anfield on Tuesday, is six years behind Liverpool and needs to undergo a major rebuild if it is to contend for titles again.
United lost 5-0 to Liverpool at Old Trafford in October and then was outclassed in the return game, as Jurgen Klopp's side returned to the top of the Premier League.
"It is embarrassing, it is disappointing, maybe even humiliating," said Rangnick.
"We have to accept they are six years ahead of us now. When Juergen Klopp came they changed at the club and lifted not just the team but the club and city to a new level. That is what needs to happen with us in the next transfer windows," he said.
The German said that Liverpool had improved under each transfer window after Klopp joined them in 2015 and that had paid off with the squad now containing "25 Formula One racing cars".
Rangnick is not expected to remain in charge of United next season with Ajax's Dutch coach Erik ten Hag widely tipped to take over as manager.
With several players out of contract, Rangnick, who also has a role as a consultant at the club, said there was going to be major movement in and out.
"For me, it's clear that there will be, I don't know what, six, seven, eight, maybe 10 new players," he said. "And then before you sign those players, you need to be aware, how do you want to play?
"What kind of football does the new manager want to play and then take it from there and then bring every single player fitting into that kind of profile.
"There will be a rebuild, for sure. But right now, that doesn't help us because we still have another five games to play," said the former Leipzig coach.