The Liverpool captain said the reigning Premier League champions must take full responsibility for a disappointing title defence and insisted significant changes are needed behind the scenes to prevent a repeat next season.

"I'm not here to make excuses," Van Dijk said. "It's been a very disappointing season, an unacceptable season. We shouldn't feel sorry for ourselves whatsoever. We have to turn it around and make sure this doesn't happen again. It's not Liverpool."

Liverpool's defeat to United — their second league loss to their rivals this season — leaves them needing a small points tally from their final three matches to secure Champions League qualification, with Chelsea, Aston Villa and Brentford still to come.

Despite a brief upturn in form prior to the Old Trafford setback, Van Dijk admitted the campaign has fallen well short of expectations.

"I think it's unacceptable that we have lost too many times as defending champions," he said. "We shouldn't accept it whatsoever. There will be a lot of work that has to be done going into next season. When I am back, I will go into it. But there is a lot of work to be done behind the scenes."

The Dutch defender stressed that consistency, more than anything, has been Liverpool's biggest issue this season, adding that the squad must rediscover the standards that brought previous success.

"At the minute we are just disappointed," he said. "Consistency is the most difficult thing in any job you do, but it's also the best way to be successful."

Van Dijk also addressed suggestions on social media that Liverpool's players have been given excessive time off during the season, firmly rejecting the claims.

"I'm not sure it's a holiday. It's a city trip," he said. "We had one day off. Everyone is an adult and decides what they do with their families. We are not kids."

He pointed to the broader scheduling picture across top clubs, referencing Manchester City boss Pep Guardiola's approach.

"You see Guardiola giving City three days off and they are doing pretty well. It's about finding the right balance," Van Dijk added.

Injuries have also disrupted Liverpool's season, with key players missing at Old Trafford, but Van Dijk refused to use that as justification.

"It's tricky, but it's the situation," he said. "I can't stand here and say that's the reason. It's down to us to turn it around."

With Champions League qualification still not secured, Van Dijk said Liverpool's immediate focus must be finishing the job before attention turns to rebuilding.

"We have the quality to hurt any opponent," he said. "We want to be playing against the best teams in Europe. We have three games left, then we reset. But this season cannot be repeated."

Arne Slot demands 'highest standards' from Liverpool in Champions League opener against Bologna