Andy Awford admitted Pompey have lost their goal threat.
And the Blues boss believes his team’s confidence has drained off the back of three league defeats on the spin.
But Awford promised his men won’t shirk the graft needed to reverse their fortunes.
Pompey slipped to a disappointing 2-0 loss at Southend on Saturday.
That continued a downturn in fortunes after League Two losses against Newport County and Burton Albion.
Awford made no bones about his side’s lack of cutting edge.
He thought that was underlined by their inability to fight back after going behind at Roots Hall.
Awford said: ‘I’m frustrated more than anything.
‘We knew how they would play and it was how they did play.
‘The two teams cancelled each other out.
‘What I’m disappointed about is that, after we went behind, it took us too long to get going again.
‘We didn’t react to going behind – that’s what wasn’t good enough.
‘In previous games we’ve gone behind and still looked a threat.
‘I don’t think that’s the case this time.
‘Once we were behind I’m not sure we did enough.
‘Confidence is a little bit low at the moment.
‘When you lose, confidence suffers.
‘But that’s what we will be working on to get back into the lads.
‘The formula is to keep working hard to put things right.’
Awford was fully aware the defeat to an out-of-form Southend was an opportunity lost.
He knows the only way to turn things around is to put in the graft on the training pitch.
Awford said: ‘We said at half-time we could win it.
‘They haven’t won many at home all season and hadn’t won in five games.
‘If there was a time to play them, it was now.
‘But we had to be solid and hard to beat after back-to-back defeats.
‘We were that in the first half. We were hard to break down.
‘We hoped it would open up, but, as we know, goals change games.
‘They got it after we had a couple of chances we should have maybe done a bit better with.
‘The set piece has undone us.
‘The attacking wasn’t there enough, though.
‘At times it was better, but we haven’t done enough.
‘We’re not going to get down about it.
‘We have to keep working at it.
‘We have to keep working hard and training hard to turn it around.’
It’s now three games in the league without a goal for Pompey.
Awford believes the blame for that should be shared.
He said: ‘It’s a collective.
‘It’s not fair to just pinpoint the strikers
‘If we aren’t creating chances we won’t be scoring goals.
‘We aren’t a threat at set-pieces at the moment.
‘We need to have more determination in the box.
‘We need better delivery at set-pieces. I didn’t have the feeling we would score from a corner.
‘There was a lack of belief and conviction after we went behind, and that’s disappointing.’