Greg Halford bemoaned Pompey’s lack of killer instinct after being held to a goalless Ashton Gate draw.
Steve Cotterill’s side collected a point on Saturday from the trip to Bristol City.
In a generally lethargic encounter, it was the visitors who came closest to claiming the victory.
During an improved second half, Luke Varney struck a post, Liam Lawrence headed at keeper Dean Gerken from close range and Dave Kitson ballooned a shot from eight yards out over the bar.
Yet the Blues couldn’t get the breakthrough their efforts deserved.
It was a second successive clean sheet, though, as Pompey moved up to 11th spot in the Championship.
Already it is their best start to a campaign for three seasons.
But Halford was far from satisfied with the outcome of the fixture.
He said: ‘I am bitterly disappointed to be honest.
‘We out-ran them in the second half and created a few chances which we should have tucked away.
‘It’s just scoring goals. At the minute it is our problem again this year, we haven’t scored enough so far.
‘Not many of us performed in the first half and I think the two games we had in quick succession really took it out of us.
‘It actually took 45 minutes for us to get our legs going a little bit but in the second half I think we deserved the three points.
‘Obviously, we are pleased with a second clean sheet in a row.
‘Bristol City didn’t really create any clear-cut chances – only when the wingers came in and shot – but they didn’t really cause us problems.
‘We are creating a few chances but we have to be ruthless.’