Luther Burrell has urged Saints to 'rebuild and push on' as they attempt to bounce back from their derby-day disappointment.
The black, green and gold were beaten 23-15 by local rivals Leicester Tigers at rain-soaked Twickenham on Saturday.
That means Chris Boyd's men have lost four of their six Gallagher Premiership games as they prepare to take a break from league action over the next few weeks.
French giants Clermont Auvergne provide the opposition in the European Challenge Cup opener at Franklin's Gardens this Saturday.
And centre Burrell said: "Saturday was a huge disappointment.
"There was a lot of frustration in the dressing room after that game.
"We went to Twickenham for the victory.
"It was a very special occasion for the club and to get behind Rob (Horne) and what's frustrating is that 60, 70 per cent of the game we outplayed them.
"We got into our structure and plan of how we want to play in conditions that were not ideal.
"We made some key errors in key parts of the game and they capitalised on that.
"We've got to address it and dust ourselves off.
"We've got to get the work done this week and focus on Clermont.
"We've got to rebuild and push on."
When asked whether the emotion of the occasion affected Saints against Tigers, Burrell said: "Absolutely not.
"How many times did it get heated out there and we managed to regroup?
"There weren't any sin-binnings and we managed to keep all our players on the field.
"What we didn't control well enough was the ball and our reactions when we made key mistakes.
"I wouldn't say emotion got the better of us at all.
"We knew what we needed to do and for the majority of the game we played well."