Successive defeats this week at the hands of Derbyshire Falcons and Birmingham Bears have left the Steelbacks' hopes of qualifying for the quarter-finals in the balance.
Their destiny is still very much in their own hands though, and with two games remaining Northants know that two wins will guarantee a place in the last eight, with one very likely to be enough as well.
The first of those matches comes on Friday against David Willey's Yorkshire at Wantage Road on Friday, which is once again on course to be a sell-out, as it was for last week's date with North Group leaders Lancashire Lightning.
On that occasion the support helped the Steelbacks turned on the style to claim a crucial victory, and Sadler wants more of the same against Yorkshire.
"The crowds have been brilliant and it was good again on Wednesday (against the Bears)," said Sadler.
"But I think the extra 10 per cent or so will help and be that 12th man we talk about.
"As always, it's a case of not getting too up and not getting too down, we were outplayed on Wednesday by a couple of their guys winning if for them.
"We will come back Friday and we will go again.
"We will keep playing that positive brand of cricket, the energetic, fast-paced, brave cricket and hopefully we can be on the right end of the result."
One man who will certainly be hoping to be on the right end of the result will be Saif Zaib, who produced two superb innings earlier in the week, only to end up on the losing side on both occasions.
The left-hander hit 92 from 58 balls at Derby on Tuesday and followed it up with 74 from 32 against the Bears, only to see the team go on and lose.
It's a familiar tale for Zaib, who also hit a half-century in the defeat to Lancashire at Old Trafford earlier in the competition, but Sadler says that can't take away how good the innings were.
"Saif is maturing into one hell of a player," said the head coach.
"It has always been in there, and he has always had the role down the order of coming in at the end and getting quick 20s or 30s, and he has been brilliant for us.
"But I think he is now ready to take that extra responsibility.
"Unfortunately for him, he has played three magnificent innings this year, and we have lost all three games.
"Arguably, those innings have been the smartest of our competition, or are certainly right up there.
"So that is unfortunate for him, but he is maturing into a fine cricketer."
Those words were echoed by skipper Josh Cobb, who said: "In the past two games with Saif, he has really matured in terms of the way he is playing.
"He is not getting 30s any more, he is getting the big scores which is getting the team into good positions, and hopefully on Friday we can finish the game off as well."
And on the Yorkshire game, he added: "We have been playing some excellent cricket and we just have to remember what we have done and just keep looking to produce that.
"But ultimately we have two games left and we have to start winning again."