Kenny Jackett has told Pompey to improve their recent defensive record.
And the boss insists it’s not just the back four who are to blame.
During the first half of the season, the Blues boasted the best goals-against record in League One as they topped the table – conceding only 19 times.
That figure has already doubled, though, with Jackett’s troops shipping 22 goals from their subsequent 14 games in the division.
The manager has no concerns over his side’s potency in the final third of the pitch, having scored the joint-second most goals (64) this term.
But he is disappointed how many Pompey have conceded of late.
And Jackett feels there needs to be an upturn not from just his rearguard but throughout his team.
He said: ‘As a side, we have tried to go forward and get as many goals as possible.
‘We're in no bad position in terms of goals scored – second in the league is a good one.
‘It’s just been one of those where we’ve conceded too many goals in the second half of the season.
‘We haven’t got enough clean sheets for the level of defenders we’ve got and are seventh in terms of goals conceded.
‘We will try to keep our attacking intent and do everything we can to keep our goals tally high but try to tighten up at the back.
‘You have to judge both as a team. It’s too simple to say your forwards score and your defenders defend.
‘For all of the forwards in the world, you need a service form the back six to feed the front four in the 4-2-3-1 system I play.
‘Similarly, defending is all over the pitch.’
The goals Pompey shipped in the 3-2 win at Walsall on Tuesday both came from corners.
Although it didn't cost Jackett’s side, he knows that standards have slipped.
The manager added: ‘We conceded two goals from corners against Walsall – the second one we had nine players inside the six-yard box.
‘It didn’t cost us on Tuesday but it’s something we need to improve.
‘We have some experience looking at our back four looking at the amount of league games they’ve played.
‘It’s just something we have perhaps slipped on and need to improve.
‘As a side, if there's a corner against you can’t just blame four people.
‘It is a team effort both ways.’