Boss Brendan Rodgers says Liverpool must shape up defensively or forget about qualifying for the Champions League.
The Reds have kept only five clean sheets in their last 37 matches and while their manager believes the seven-point gap to Champions League places is by no means insurmountable, they will have to do considerably better at the back.
"There is always a period of pressure you will come under," said Rodgers.
"You can have the ball a lot of the game and you will still have to defend at some points in that game.
You have to remain calm; the single biggest thing has been mistakes. It is not so much structurally but we have a tendency at times to make mistakes and that has cost us.
"You have to remain calm; the single biggest thing has been mistakes. It is not so much structurally but we have a tendency at times to make mistakes and that has cost us.
"That is something we work hard to get the players to eradicate from their game.
"From the Crystal Palace game (when they lost 3-1 in late November) we needed to change, get back the model of our work, and from that we have slowly got back to a decent level again.
"There is still a lot of work to do but part of that is to ensure we don't give away silly goals."
West Ham, Arsenal and Tottenham stand between Liverpool and Southampton in fourth but Rodgers remains confident, with the imminent return of striker Daniel Sturridge from a long-term thigh injury, it can be achieved.
"It's going to be tough but I am looking forward to the challenge," he added.
"We have a great spirit at the moment and footballing ideas are returning to our game and will push very hard in the second half of the season to bring success here.
"The players are improving and we can see how seven points may seem a lot but it certainly can be whittled away.
"You just have to consistently win games and perform well and that is our idea."
Rodgers has already said he does not expect to make many, if any, additions in the January transfer window despite continually being linked with numerous players.
Rodgers was non-committal on the latest speculation surrounding Manchester City's James Milner.
"James is a wonderful player, an outstanding footballer, but players get linked consistently here through agents trying to, by virtue of association, get a better deal," he added.
"I will never speak about any player until they were signed in the door. You can fire a list of names at me and you will get the same response."
Rodgers also does not expect many departures, apart from possibly on loan.
"If everyone stays there might be a few who need to go out on loan because they are not playing so much," he said.
"At this moment I wouldn't envisage too many departures."