Paul Cook ripped into Pompey for the defensive lapses which are ruining their season.
And the Blues boss admitted his side’s inability to turn dominance into victories is hampering their ability to be promotion contenders.
Saturday’s 2-1 defeat to Notts County showcased the recurring problems which are proving so costly for Cook’s side.
Pompey failed to make the most of controlling the first half against the Magpies.
And they were undone by a sucker-punch by Adam Campbell after 21 minutes when in the ascendancy.
It was an easily preventable goal from a set-piece in Cook’s eyes.
He is being left as frustrated as the Pompey fans who greeted their second home defeat on the bounce with boos on the full-time whistle.
Cook said: ‘The goals we give away we will concentrate on. We keep conceding poor goals.
‘We used to be so solid. Now we need to go a goal behind to get going.
‘Having the momentum we had we shouldn’t be a goal behind.
‘It’s concentration. It’s little lapses and we must suffer when it happens.
‘You can’t be giving teams goal starts at home. It’s happening all the time.
‘I enjoyed watching us play in the first half. We were a threat and I enjoyed watching us play.
‘We had chance after chance and had everything.
‘We shouldn’t concede the goal, it’s so easy to stop. It was avoidable to say the least.
‘That’s two goals from set-pieces now lately.
‘Doncaster’s second and that. We switch off. And if we switch off we get punished.
‘Your two centre-halves have one lad to deal with. Concentrate.
‘We concede goals which give us mountains to climb.’
Cook afforded praise for the manner in which Notts County carried out a smash and grab after being under the cosh for 45 minutes.
But he feels John Sheridan’s side didn’t offer a significant threat to his team.
Yet, Pompey contrived to fall to their fifth league defeat of the campaign in front of a crowd of 17,269.
And they did that despite dominating possession and carving out 17 shots on goal to the visitors’ five.
Cook said: ‘Notts County didn’t have a lot of chances.
‘It’s a great win for them. They dug in during the first half and stayed in it.
‘But when you play that well you can’t be coming in drawing 1-1 at half time.
‘The game should be done and dusted.
‘We looked full of life in the first half and a great team to watch.
‘When you have that much dominance you can’t be drawing the game.
‘We didn’t play well in the second half. We didn’t get going although maybe got a little bit of momentum after the sending off.
‘But it’s not good enough.’