Boss Jimmy Floyd Hasselbaink says the Cobblers players have to improve their concentration levels to avoid any repeat of the second half collapse they suffered at Southend United on Saturday.
Leading 2-0 and coasting at the interval, Town threw away all that good work as they conceded twice in the opening five minutes of the second half to ultimately draw 2-2.
Hasselbaink felt it was two points thrown away by his side, but perhaps more worrying for the manager was the game followed a similar pattern to his first two games in charge.
Although Doncaster Rovers and Portsmouth were both beaten, Town were under a lot of pressure in the second half of both matches, and against Pompey, as they did against Southend, the Cobblers conceded a goal just minutes after the restart.
Hasselbaink was a frustrated man following the draw at Roots Hall, and says the slow starts to the second half of matches is a habit the team has to shrug off quickly.
"It is frustrating, but I think the players are frustrated," said the Cobblers boss.
"We need to get out of that habit, get out of that way, and move on, and we have to make sure now that it doesn't stick in the head.
"We have enough experience, but I just think it is about know-how, about confidence.
"It is one thing to do it and work, and not thinking we have done the job.
"The majority of matches now are 96 minutes, 98 minutes long and you can't just work for 45 minutes.
"It feels disappointing, it feels like it is two points lost, but we have to keep on working and keep on improving.
"We have to keep on working on our organisation and the team ethic."
Hasselbaink is also concerned that throwing away the 2-0 lead on Saturday may now play on the minds of his players, who are back on the road on Tuesday night when they travel to Wigan Athletic.
"If you get something out of the game away from home it is always good, but leading 2-0 if you do your work then you go away with a win, in that way I am a little bit greedy," said the Town manager, who has overseen two wins and a draw in his first three games in charge at Sixfields.
"To have been 2-0 up and to draw 2-2, that puts doubt in the back of the players' mind.
"If it's a 0-0, you can build from that, even though it is the same kind of result and you get a point, when you are 2-0 up and draw 2-2, it is the back of your mind for the next match."
And he added: "I think we had kept it at 2-0 that would have been immense for the players' confidence.
"What happened will hit the confidence a little bit, but I have some talented players here.
"We just need to work to make ourselves a better side, a more together side, to make sure we are organised and playing from the right platform.
"We have to do that together, not individually."