The festive period has yielded just two points from three League One fixtures for table-topping Pompey.
A draw with Fleetwood just before Christmas was followed by defeat to Bristol Rovers and a goalless stalemate at Exeter.
There were few clear-cut chances created in the latter contest, although Colby Bishop and Paddy Lane both went close to scoring.
Sean Raggett admitted it was a disappointing evening to end 2023, but has faith that the Blues can get back on track.
The defender said: “Frustration just about sums things up because we weren’t quite at it – especially in the first half.
“We came out after the break and were a bit better, but I would still expect to see more from us because we didn’t create loads.
"There’s quality here and the strength in depth is better than it has been in the past, which is a big thing."
“There were still enough chances for us to win the game, though, and we were the team in the ascendancy.
“We just need to be a bit braver and show some more quality on the ball to make sure that we improve on this.
“Things just didn’t quite go our way, but that happens sometimes and if you look back over the season, we’ve had late winners and moments go for us.
“So it’s disappointing, but we’ll take the point and the clean sheet, then move on to Stevenage on Monday.
“The boys are fully confident in this group and know this has just been a small blip for us. We’ve got what we need to be successful.
“There’s quality here and the strength in depth is better than it has been in the past, which is a big thing.”