Pompey’s three successive away games on the road have yielded just a single point.
But with just two goals conceded during that run, Clark Robertson knows that they need to improve at the other end of the pitch.
The Blues failed to make the most of a dominant period at the start of the second half, allowing Ethan Robson to secure victory for the hosts.
Ahead of back-to-back home games, however, Robertson is confident they can quickly get back on track.
Pompey’s skipper said: “We allowed our opponents to get into their stride far too easily in the first half.
“MK Dons are obviously a very good team and you can’t allow them to get a foothold in the game like we did.
“There were a few chances in the first half and we had to defend well, while Gav was excellent in goal once again.
"You want to keep clean sheets, but at the same you need to be scoring if you want to climb the table."
“But we regrouped at the break and for the first 20 minutes after it, I thought we had complete domination.
“We got a corner kick and they broke away to score the only goal, which has taken the wind out of our sails.
“We didn’t respond as well as we should have after that and didn’t pose MK Dons too much of a threat.
“I think we’ve been fairly comfortable defensively this season and have only conceded twice in six league games.
“You want to keep clean sheets, but at the same you need to be scoring if you want to climb the table.
“It’s something we have to work on during training because it’s down to all of us and the final ball is letting us down at the minute.
“Hopefully that will come in the coming weeks because we can’t afford to dwell on things and want to start picking up points again.
“There are still a lot of players trying to gel together, but I think we’ve got the makings of a good team here.”