Captain Chris Barker wants Southend to extend their three-game unbeaten run at Swindon on Saturday but knows his defence must improve.
The Shrimpers currently lie ninth, despite conceding nine goals in their six league games this season, but the centre-back knows clean sheets are needed if they are going to push up the league.
"We do a lot of work on our back four and the back six but you wouldn't think we did at the moment because we're letting in too many goals," he told the Echo.
"We kept 12 clean sheets last season but only have one in the league this year so we know we need to start getting a few more if we are to be in the hunt for promotion."
The defensive problems were evident at the weekend when they surrendered a two-goal lead to draw with Northampton but Barker is remaining optimistic.
"Drawing with Northampton has made that three unbeaten for us and we want to keep the run going when we go to Swindon on Saturday," he added.