It was a flat performance in a flat game as the League One promotion hopefuls dropped two points against relegation-threatened opponents with only two wins from their previous 16 games.
Butler's team saw plenty of the ball, but the interim manager blamed a lack of urgency for failing to make the most of it.
“I didn't think we played with any sort of urgency or tempo,” said the interim manager.
“Northampton obviously set their stall out for a 0-0 and a break or a set-piece so we had to be switched on for that, which we were, but we're so much better than that.
“It was just the way we moved the ball, we allowed them to get back into their shape. I'd rather dictate the tempo, that was disappointing. We're usually a free-flowing football side but Northampton came with a gameplan to stifle and they did that.
“We spoke pre-match about how playing with some sort of tempo and urgency would move them about but it's just not happened. We never really threatened. There was a bit of urgency towards the end but it was disappointing.”
Butler took charge promising entertaining football, and admitted they had not delivered. It was their first 0-0 draw since they played at Sunderland in January 2020.
“The players have got standards and I'm not going to say it was a vintage Doncaster Rovers performance,” he said. “We can still improve and that's what we've got to do. We've got to get better and better and better.
“On a positive it was a clean sheet, so the defenders did their job on set plays and open plays.
“The defending from set pieces and the way the players organised off the ball was good. On the ball was good, possession was good, but it was just that creative edge.
“Maybe it was a little bit of fatigue coming in.
“It's not all doom and gloom we're still in a fantastic position but it's something to work towards.
“The whole team defended well it was a team effort.
“We've strill a long way to go yet.
“That's how far we've come to be disappointed by a 0-0 but we've still got a long way to go.”
The best chance of the game fell to the Cobblers, with Ryan Watson inadvertently stopping a corner from Rotherham United loanee Mikel Miller going into the net.
Josh Sims, Omar Bogle and John Bostock missed the game through injury, and are unlikely to face Oxford United on Tuesday.
On Sims, he said: “We've got to send him to the specialist to have a look because it's something we have to get right. It could just be a trapped nerve.
“It might settle down but we've got to make sure we do right by Josh.
“(He's had it for) a couple of weeks but he only really flagged it up this week and said he felt no power in his left leg.”
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