Reeco Hackett felt that Pompey were undone in both boxes during their League One defeat at Plymouth.
The forward came off the bench to reduce their deficit after Sam Cosgrove and Finn Azaz had given the hosts a commanding lead.
Argyle netted again through Ryan Hardie following a quick stoppage-time break to seal a 3-1 victory that sent them back to the summit.
Hackett felt that the Blues could have been pleased with their performance in the centre of the pitch, but knows more work needs to be done.
He said: “It wasn’t the greatest performance from us, although we did create the chances to get a few more goals.
“The ones that we gave away were too soft, but I thought we were probably on top between both boxes.
"The honest truth is that we should be doing better because we do back ourselves and so it’s disappointing."
“It’s always going to be tough because Plymouth are in good form and we’re still developing under a new manager.
“We’ve done well and it’s just those final parts at both ends of the pitch where we haven’t quite been good enough.
“The honest truth is that we should be doing better because we do back ourselves and so it’s disappointing.”
Hackett has been limited to a couple of substitute appearances since John Mousinho took over as head coach.
He said: “The gaffer has been really positive and our game has probably been simplified, with more of a licence to express ourselves.
“I haven’t played too many games, but have been working hard behind the scenes to get those opportunities.”