Pompey have one of the better defensive records in League One.
And only the two sides in the automatic promotion places have conceded fewer than them on home soil.
Luke McGee is a key reason for that, with the goalkeeper yet to miss a minute of league action so far this season.
But the 22-year-old summer signing from Tottenham believes there is still plenty of room for improvement.
He said: “We’re always looking to progress and haven’t had as many clean sheets in the past few games as we would have liked.
“That’s always the goal for me – both on a personal level and, of course, because it helps the team if you’re not conceding.
"I take little bits from them all the time in training because I want to improve my all-round game if I can."
“Working with (goalkeeping coach) John Keeley and Alex Bass, as well as the rest of the coaching staff, has helped me.
“I take little bits from them all the time in training because I want to improve my all-round game if I can.
“There isn’t really one specific area that I’m focusing on and I’m just working hard to make sure my performances get better.”
Pompey’s latest outing saw them draw 1-1 Scunthorpe, as Jamal Lowe’s opener was cancelled out by Kevin van Veen.
McGee said: “It was a good point against a top side who are a few places above us in the league table.
“The lads defended well and the forwards kept the ball well, so I think it’s a performance we can be pleased with.
“We worked on the new system in training and I thought Nathan Thompson was outstanding in front of the back three.”