Jim Mallinder expects Glasgow Warriors to come out all guns blazing at Franklin’s Gardens on Sunday evening.
But he is hopeful his team can produce a repeat of November’s success at Scotstoun Stadium as they bid to enhance their chances of reaching the Champions Cup last eight.
Saints are currently second in Pool 3, one point ahead of the Warriors with two games to go.
Racing 92, who host Scarlets this weekend, are expected to win the group, leaving Saints and Glasgow battling to try to secure a best runners-up spot.
Mallinder’s men know they must win their final two games to stand any chance of making the quarter-finals.
And the director of rugby said: “We said it from the start of the season - it’s going to be full on, every game is going to be important and it’s proven to be that way.
“In terms of our European ambitions, we need to win.
“We went up to Glasgow in November and put in a very good performance, we had to work very hard for that (26-15) win up there so we know we can beat them, but we know they’re going to come here and test us.
“It was one of them (best performances of the season), we’ve had an inconsistent season but the Glasgow away game was one of our better performances.
“They’ve still got a chance so they’ll come down with a very attacking team, that’s the way they like to play their rugby, we’ve seen that over the last couple of years, and they’ll look to challenge us all over the field.”