Chris Boyd says Saints will be 'fighting for our lives' when they face Harlequins at the Stoop on Saturday afternoon.
The black, green and gold need a victory to ensure they remain in the Gallagher Premiership play-off picture.
They dropped to seventh last weekend, having lost 40-31 to third-placed Gloucester in an eventful clash at Franklin's Gardens.
And now they travel to fourth-placed Quins, who are currently seven points ahead of Saints with four games to go.
"It's a big challenge," Boyd said.
"They need points, we need points, everybody needs points - it's that time of year.
"We'll all be fighting for our lives, like they will be, so it will be a real contest.
"They've had some really good victories against some really good sides and then they've been a bit average against some not so good sides.
"They've been a little bit up and down but currently sitting fourth in the table would suggest they've had more ups than downs and that's a fair evaluation of their season.
"They will be very pleased with where they've shifted from last year's position when they were 10th.
"They're fourth and it's a good improvement."