David Ripley has urged his Steelbacks players to learn a lesson from the time penalty that cost them six runs in their shock defeat to Leicestershire Foxes on Wednesday evening.
Northants were beaten by four wickets by the Foxes in the Vitality Blast opener, having set the away side an eye-watering 219 to win.
At one stage, Leicestershire needed approximately 16 runs per over to prevail, but they eventually got home to seal a stunning success.
Colin Ackermann's 66 from 31 deliveries proved key, with the Foxes captain smashing a six to win the game with two balls to spare.
But Northants were left to rue a slow over rate, which cost them six runs when Leicestershire needed 26 from 10 balls to win.
And Ripley said: "That is the thing that's the toughest to take.
"We can have guys not being at their best but we've just got this malaise about us.
"It's like we don't look at the bottom corner of the scoreboard that tells us the time.
"It doesn't seem to bother anybody.
"On the sidelines, we're always conscious of it in every competition other than the 50 overs in which you've got an eternity to bowl your overs.
"We've been here before, dodging the clock, and we're here again in the first game.
"We've avoided it up to now and in some of those cases the umpires have been overgenerous.
"But tonight the umpires were fair, they did their job and that extra six runs when you're defending, makes it difficult.
"Rory (Kleinveldt) probably doesn't go for that Hollywood ball that conceded four wides in the last over if we hadn't lost those six runs.
"It was a very key part of the game and one we will hopefully learn a lesson from because it's not the first time it's happened to us."
Ben Duckett had blasted a superb 96, with Josh Cobb (56) and Alex Wakely (51no) also impressing as Northants racked up a huge 218 for three.
But it wasn't to be enough and questions were posed as to why spinner Graeme White didn't bowl at all during the Foxes reply.
"Graeme was fine," Ripley said.
"The captain has held his hands up a little bit on that one because he felt he should have got him into the game.
"What I would say is at the time we needed that spare over with five to go, (Mohammad) Nabi and Ackermann were in and they are good players of spin.
"It was a tough call for Alex to bring Graeme on for what was going to be one make or break over so he went with Steven (Crook), who had already had a contribution in the game.
"Alex feels with hindsight that he could have let Graeme go out and have a duel and try to win that battle.
"Graeme is one of our accomplished white-ball bowlers and he hasn't bowled a ball.
"Alex has held his hands up with the group and perhaps he would have done that differently."
On the performance as a whole, Ripley added: "We're very disappointed.
"It was a tale of two halves. The first half was outstanding because we lost an early wicket but still played with power and conviction in the powerplay.
"Ben and Cobby were really good and Alex also added a little bit so we obviously thought we would defend that.
"At one stage, it went to 16 an over for a number of overs in their reply so there are a lot of disappointed lads up there.
"We haven't done ourselves justice with the ball and in the field. We were sloppy in the field, letting balls go over the boundary and we had a dropped catch, which was pretty crucial.
"We've not had a good second half and although we could still have got over the line, we didn't show the calmness we needed.
"We were frantic, that's why we lost time, rightly so because we were sloppy, we weren't in position quick enough and that led to them getting on top.
"It was a very fine innings from him (Ackermann), but that happens in T20 cricket.
"We didn't seem to have a good plan A, know where our field needs to go and we got muddled on a ground that is difficult to defend.
"But we have to defend in that situation and it's those tight ones that slip past you that you look back on.
"It's not ideal."