Brendan Rodgers concedes Liverpool's season is destined to end in frustration unless his side can plug the gaps in their leaky defence.
The Reds have kept just one clean sheet in their last 18 matches and Rodgers' pre-season overhaul of the defence, which saw the Liverpool manager splash out on Dejan Lovren and Alberto Moreno, has so far failed to solve the problem.
This season Liverpool have shipped 19 goals and a weakness dealing with set-pieces has contributed to several defeats, including Wednesday's 3-0 loss against Real Madrid in the Champions League.
Liverpool are already nine points behind Premier League leaders Chelsea heading into Saturday's clash with Hull at Anfield and Rodgers knows there needs to be an immediate improvement at the back to avoid losing touch with the top four.
"Defensively we need to be better as a team, not just the defence and goalkeeper," he said.
"We all pride ourselves on clean sheets but we need to be more competitive and aggressive in those moments as a team.
"That was the disappointment against Real Madrid and also the goals we have conceded a large number of them have been soft and it is our job to improve that quickly.
"We need to work harder and make it better."
Meanwhile, Chelsea manager Jose Mourinho says Spain striker Diego Costa could climb off his sick bed to face Manchester United on Sunday.
Costa missed Chelsea's last two matches with Crystal Palace and Maribor due to a hamstring problem and also spent a night in hospital earlier this week due to a virus, but could feature at Old Trafford.
"Diego has a little chance," Mourinho said. "I'm not saying he can (play). I'm saying that we are trying. We will see what happens between Friday, Saturday and Sunday.
"Everything happened to him. He was obviously injured and he had to go to the hospital with a viral situation that we didn't manage to resolve without being in hospital over one night."
- Chelsea won't cry over injuries -
Despite his injury problems, Mourinho is confident Chelsea can maintain their unbeaten start to the season.
"We are playing well, we are getting good results," said Mourinho. "We don't cry about injuries. We just think one injury means an opportunity for somebody else."
Sunday's match pits Mourinho against United manager Louis van Gaal, who kept the Portuguese on his staff at Barcelona after he had been first brought to the Spanish giants by former England manager Bobby Robson.
But with United, having laboured to a 2-2 draw away to West Bromwich Albion last time out, Dutch manager van Gaal knows it will take more than a detailed knowledge of Mourinho's methods for his side to beat Chelsea.
"Now we have to play against Chelsea and in the Netherlands they say 'that is another Kuche', or another 'biscuit'. By that I mean another level," van Gaal said.
Southampton may have lost several key players, as well as manager Mauricio Pochettino, to rival Premier League clubs in recent months but that hasn't stopped the Saints soaring to third in the table.
Last week they recorded their biggest top-flight win when they thrashed Sunderland 8-0.
Southampton also boast the meanest defence in the Premier League so far this term, having conceded just five goals in their opening eight matches.
Nevertheless, manager Ronald Koeman believes the south coast side, who face Stoke at St Mary's on Saturday, still have room for improvement.
"We showed them some clips from the first 20 minutes against Sunderland," said Koeman.
"That's not how I like us to start at home. They know what happened -- it wasn't a good start," the former Netherlands defender added.
That defending champions Manchester City are second in the table, five points behind Chelsea, is no surprise but West Ham in fourth place certainly is.
City travel to the London club's Upton Park ground on Saturday having let slip a two-goal lead in a 2-2 draw away to CSKA Moscow that left them in severe danger of failing yet again to qualify for the knockout stages of the Champions League.
Fixtures (1400GMT unless stated)
Saturday: Liverpool v Hull, Southampton v Stoke, Sunderland v Arsenal, Swansea v Leicester (1630GMT), West Brom v Crystal Palace, West Ham v Manchester City (1145GMT)
Sunday: Burnley v Everton (1330GMT), Tottenham v Newcastle (1330GMT), Manchester United v Chelsea (1600GMT)
Monday: QPR v Aston Villa (2000GMT)