The Red Devils were comprehensively beaten 4-0 by Liverpool at Anfield to further dampen their chances of qualifying for the Champions League.
Goals from Luis Diaz, Sadio Mane and a Mohamed Salah brace ensured Manchester United lost heavily to Liverpool for the second time this season, having lost the corresponding fixture 5-0 at Old Trafford back in October.
Rangnick started the game with a back three but was forced to revert to a back four after Liverpool completely dominated the first and the German was critical of his side’s display which left them in sixth position on the table.
"It is embarrassing, it is disappointing, maybe even humiliating. We have to accept they are six years ahead of us now," he told BBC Sport.
"When Jurgen 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."
"I don't think a different formation at the start would have changed anything," he continued. "The first goal we conceded, it was not part of the game plan to be that high up and concede a counter-attack after five minutes. That changed the game.
"The first half, we were just not good enough. We did not win any first ball or second balls. We were second best in all relevant areas.
"Second half we changed a centre-back with Jadon Sancho. The first 25 minutes we were better and had pressure on the ball at times. We had two or three moments, but the third goal killed the game off.
"For the third goal it came from a ball we should not play. A pressing invitation: 12 yards into Anthony Elanga, who is a player for [running] behind their back line.
"It is inviting them for those moments and six seconds later the ball was in our net."
