Pompey beat Crawley 9-1 when there were no fans present at the weekend, only to lose when more than 1,200 turned out to cheer them on against AFC Wimbledon.
An unfortunate Ben Stevenson own-goal midway through the first half was enough to see the League Two side triumph at Plough Lane.
John Mousinho knows those two contrasting results mean very little, with the competitive action not getting started for another 11 days.
But he is aware there is plenty for them still to work on ahead of that league opener against Bristol Rovers.
The Blues boss said: “It was disappointing to lose and we probably deserved to, although there were some good spells in there.
“We were a bit sloppy in possession and gave the ball away a few too many times, so there’s plenty to work on.
“A positive is the amount of chances we created in the second half and finding the net – which we didn’t have any trouble doing at the weekend – is the next step.
"We were a bit sloppy in possession and gave the ball away a few too many times, so there’s plenty to work on."
“We didn’t get carried away after the Crawley game and we’re not going to get too down after this one because the most important thing is minutes.
“It’s never going to be smooth with so many new signings coming in – across the front six, five of them arrived over the summer.
“This is the time to get those teething problems out of the system and there are plenty of training sessions left – plus another game on Saturday – before we start league action.”
Colby Bishop and Sean Raggett were both absent when the teams were announced, while Paddy Lane limped off late on.
Mousinho said: “It was just a bit of fatigue for Colby after the weekend because he hadn’t featured since we played Europa.
“Sean picked up a back spasm yesterday, but he trained this afternoon and so it’s already looking better for him.
“It’s too early to say about Paddy. It didn’t look great when he was limping off, but he seems a lot better and can now put pressure through his ankle.”