Sarries were beaten 25-16 by Toulon at Stade Felix-Mayol on Saturday night, bowing out of the Challenge Cup at the semi-final stage.
But the bid for Gallagher Premiership glory is still very much on track for Mark McCall's men, who sit second in the standings with two games to go.
The first of those two matches comes against Saints at StoneX Stadium on Saturday evening (kick-off 5.30pm).
And Saracens know that a win would make sure of a top-two finish and a home semi-final in the play-offs.
England fly-half Farrell said: “We are obviously disappointed with the result (at Toulon) but probably more with the performance, especially in that first half.
“I feel like we could have given a better account of ourselves, especially in some areas we pride ourselves on.
"We will have to look inwards now, and we need to make sure it spurs us on for the rest of the season.
“We couldn’t string too much together. Massive credit to Toulon in the way they defended, and how they slowed down our breakdown in particular.
“It was hard to play against. We need to make sure we figure out why, and make sure it doesn’t happen again.
“People will feel the way they are feeling, and we will have a look at it. We’ll get straight on to it.”
Saracens boss McCall echoed Farrell's feelings.
“Yes, I think that’s spot on,” McCall said.
“It didn’t feel like we dealt with the occasion all that well. It was our first time back in an occasion like this.
“We need to see what we can learn from it. I’m not sure who did or who didn’t (play well) but it doesn’t take many for your team to be off.
“Toulon were supercharged, and the crowd was as well.
"We’ve got four or five weeks left of the season, and we can get something from this experience and take it into the rest of the Premiership season.
“I thought in the first half we got harassed into doing things we didn’t want to do. Our fundamentals weren’t great in the second half.
“Our lineout wasn’t good, and without that foundation and platform it’s very hard to play when you’re up against a team like Toulon who are on fire and as aggressive as they were.”