The Pool 4 leaders travel to France with New Zealand coach Wayne Smith content with the Saints' tight defence but aware that Agen in front of their passionate home crowd present a formidable hurdle to clear in the race for last eight places.
"We are pretty pleased with our performances in the tournament so far - particularly our defence," said Smith. "We had targeted that area and at the moment we have the meanest defence in the Heineken Cup, having conceded just 30 points in four games.
"However, we have got our two tough ones coming up and it will all mean nothing if we don't win against Agen and then Llanelli Scarlets.
"No-one is expecting us to go over there and deal with their pack - they are saying we will get munched up - and we know we have to win that battle up front.
"We were pretty pleased when we heard the result in Agen last weekend because if the Scarlets had won that one, they could have been out of touch but now it is only the try count that separates us.
"Agen's win over the Scarlets means they have lost just one of their last 53 home games - and that tells you exactly how big the challenge is for us on Friday night."A record like that does not mean that you cannot do it, but we are going to have to be spot on mentally and physically to pull it off."