Nicky Shorey believes it is time Pompey rose to the requirement of performing over 90 minutes.
The Blues turned in a dour and largely uninspiring display during Saturday’s 1-1 draw with Mansfield Town.
Defender Paul Robinson’s first goal for the club 20 minutes from time cancelled out Simon Heslop’s 46th-minute opener.
That signalled a greater attacking threat as substitutes Nigel Atangana and Patrick Agyemang made a notable impact for Andy Awford’s men in the latter stages.
For Shorey, it was a finale of sustained pressure from the hosts against the Stags which could have yielded a victory.
As it was, a fourth consecutive League Two draw was collected and there were strains of booing at the final whistle of what was an instantly forgettable match.
Pompey’s left-back is aware great consistency over the duration of the game is a necessity if they are to start picking up victories once again.
Shorey said: ‘I think we can play better, definitely, there is a lot more in the tank.
‘There have been bursts here and there where we have shown our ability.
‘On Saturday, in the last 25 minutes, we showed the quality we possess and power we have got – but we need to show that more in games and for a longer period.
‘We need to start putting it together for a proper performance for a whole game.
‘Sometimes it is good enough to do that for 20 minutes to win the game but at the minute we are finding it a little bit difficult.
‘Probably looking at it, Mansfield will be saying they deserved a draw,
‘I just feel the pressure we had in the last half-an-hour, we should have won it.
‘It started pretty average and got increasingly better towards the end of the game and I think we were happy with the last section of it, without a doubt.
‘If we play like that for most of the games I don’t think we will have a problem.
‘But the first half was flat, sometimes that is the way it goes in football, you can’t be on top form all the time.
‘We need to find a way to shake ourselves out of it – 45 minutes is too long to be flat.
‘Obviously the opposition will be happy with that but being at home we need to spark the fans into life.’
The draw saw Pompey drop to 12th in League Two, although just two points off the play-off spots.
Regardless, it is a frustrating spell for the Blues, who Shorey insists are not hampered by confidence issues.
He added: ‘Coming into the games we feel confident.
‘We haven’t lost the matches, what we do need is to keep believing in what we are doing.
‘Sometimes there are thin dividing lines, a little bit of luck here and there, take a chance and it’s different. In a few of those games, if we took a chance we had earlier, such as Hartlepool away and York a little bit, then we are cruising and you can relax.
‘But we haven’t and the longer the game goes on the more frustrating it becomes.
‘We have just got to keep believing and creating the chances we are and I am sure they will soon go in.’