Newcastle had lost 3-0 at home to local rivals Sunderland in their previous game at St James' Park, but turned in an even more disappointing display against a rampant Liverpool.
The result leaves the Magpies five points outside the relegation zone with three games to play and Pardew is demanding an improvement ahead of next week's trip to West Ham United.
"Well I'm worried, of course. You can't come off a defeat like that and the manner it was without being worried," said Pardew.
"I'm not going to criticise my players, I'm not going to criticise the team in any shape or form on an individual basis.
"It was a collective effort and we fell down collectively."
Asked if he was confident he can drag the club out of a terrifying tail-spin, Pardew said: "Yes, of course, and I think we have got enough in the dressing room to do that.
"We haven't become a bad staff or a bad set of players overnight. But we definitely need to roll our sleeves up and make sure we make a really good fist of these last three games."
Pardew and his players were booed from the pitch both at half-time and on the final whistle after capitulating in alarming style, much as they had done against Liverpool in December 2008. Five months later, they were relegated.
Asked about the fans' jeers, Pardew said: "They have got every right to. That performance is just not good enough for Newcastle.
"We are all aware of that, not just myself and my staff but my team, and on Monday morning at 10.30am I expect to see all my team out there whether their foot is hanging off or whatever ready to train.
"Now we have got to show we have got the heart for this little scrap we are in because other teams certainly have."
Pardew is hoping that captain Fabricio Coloccini will be fit for the trip to east London, when Newcastle will face former manager Sam Allardyce and ex-striker Andy Carroll.
The Magpies boss added: "We've had two really tough days at home, there's no doubt about that, and today in terms of the performance was below Sunderland.
"We've got work to do, but fortunately our skipper is available and he is going to have to come back into the team and give us leadership and experience."
Pardew also conceded that his team may be suffering from a lack of Premier League experience, commenting: "I thought that was evident today, but there is enough experience in the group to get over that.
"Luckily, we've got three games to go to put it right. We have to get a win, or maybe four points at least, to make sure we're safe."