Cobblers boss Keith Curle says his side must improve their 'game management' after Saturday's 'horrible' 3-2 defeat against Cambridge United.
Town twice took the lead at the Abbey Stadium, nudged in front by Aaron Pierre in the first-half and then Junior Morias shortly after half-time, but Jevani Brown and George Taft pulled United level on both occasions.
Cambridge also missed a penalty in a hectic and action-packed second-half, but that would be forgotten by full-time thanks to David Amoo's dramatic stoppage-time winner as he lashed home after the ball ping-ponged about in Town's penalty box.
Curle was handicapped by injuries to Sam Foley, Shaun McWilliams and George Cox either before or during the game, meaning his midfield was made up of teenagers Scott Pollock, on his debut, and Jay Williams.
Curle praised the performances of both but admitted his side lacked physicality as a result.
"It would be an understatement to say that was a horrible way to end the game," he said.
"We just needed a bit more robustness, which you get with more experience, but we had our opportunities. We had a great chance to go 3-1 up when the lad nicked it off Junior's toes inside the six-yard box but there are areas we still need to improve on.
"We need to improve game management and understanding defensively that having numbers back isn't always an advantage. The positional play and understanding will improve and it needs to improve.
"The more people get used to the elements I'm trying to bring in the team and the more familiar we get, we'll be able to iron them out slowly."
Curle was unhappy with the his side's defending for the first goal when Rushian Hepburn-Murphy was allowed to tee up Brown, and also referee Martin Coy's decision to award United's penalty.
He added: "Their first goal comes from the lad being on the ground and he's able to manoeuvre the ball while he's on the ground and that can't happen. You have to get your feet involved in it and you keep him on the ground.
"You stay goalside and make sure he can't pass or play the ball but sometimes the players might have been waiting for a decision for obstruction because he trapped the ball between his legs.
"I've had the benefit of looking at the penalty decision but he's given it when the lad is a yard outside the box and that effects the flow of the game. It's not a criticism of the referee but he's given a penalty a yard outside the box because of information he's been given."