Kenny Jackett has demanded Pompey up their attacking threat after shoring up their early-season defensive problems.
The Blues lacked ingenuity and guile as they were held to a goalless League One draw with Gillingham on Saturday.
Despite monopolising possession, the hosts were unable to make a breakthrough at Fratton Park.
Pompey were solid throughout at the back, though, and recorded a second clean sheet in three matches having now settled down their rearguard.
Yet Jackett stressed that solidity in defence has to be a base for his troops to be more creative going forward.
And the boss accepted the Blues didn’t do enough to clinch all three points against the Gills.
Jackett said: ‘The positive of it, not just on Saturday but generally, is we look quite solid defensively.
‘That has helped us in recent league games and that is good.
‘But similarly, that is only a base to go off.
‘You have to build on that and in terms of creating scoring goals, we need to do more than we did on Saturday.
‘The defence does look more solid than it did early season. Hopefully we can continue to do that.
‘But we need more than that. That is just a base you work off and the goals-against column is something you obviously need to address.
‘We feel we're on the way to doing that, but as a side going forward we've got to take responsibility to make the play and the game. We didn't do enough in the second half.’
A well-organised Gillingham had a clear gameplan to sit back, keep their shape and ensure Pompey had to work hard for their openings.
Although the Blues had several decent opportunities – with Sean Raggett heading against the post in the first half and Lee Brown missing at the death – they were few and far between.
After 10 games, Jackett’s troops sit 16th in the table despite firmly having designs on promotion at the start of the campaign.
And the Fratton Park manager accepted his side dropped two points against Steve Evans’ men.
Jackett added: 'Whatever the opposition does is up to them.
‘It's up to us to negate it and do well for ourselves.
‘The game was there for us. It was two points lost, definitely, rather than a point gained.
‘It's up to the opposition to play how they want but then up to us. We lost momentum in the second half and couldn't build it up.’