Saracens defence coach Alex Sanderson admits his side have reasons to worry ahead of their Gallagher Premiership season opener against Saints.
The two clubs will renew their rivalry at Allianz Park on Saturday, October 19 as the league gets going.
Saracens will be defending the title they won by beating Exeter Chiefs in a dramatic Twickenham showpiece last month.
Saints also enjoyed a strong campaign, finishing fourth before losing to Exeter in the play-off semi-final at Sandy Park.
And Sanderson said: “The opener is going to be a tough game.
"Saints have made massive strides with Chris Boyd - he’s a good coach. He’s put real confidence into some of his younger players as well – particularly in the backline.
"If you look at the stats, they’re probably the best attacking team in terms of yardage.
“They’re able to score long-distance tries with some of the attacking prowess of a team almost in the Hurricanes making, it’s that kind of style that means they’re able to score from anywhere.
"And that’s just off the back of one season - the longer you work together the better you fit together, and I can only imagine that that’s going to be up a level again with another pre-season.
"For a defence coach, that’s worrying – how you’re going to be able to contain them.”