And Biarritz coach Patrice Lagisquet accepts that a defeat at the home of the 2000 Heineken Cup champions will leave their quarter-final hopes resting with others.
"It's clear that if we lose on Saturday, we will no longer be in control of our own destiny," said the former France wing. "We would then have to wait for the Ulster-Northampton result and go from there. However, maybe we'll get a win at Northampton to still be in the race.
"A lot depends on whether Matt Dawson and Ben Cohen are fit to play. I have seen their recent matches, including their loss at home to Gloucester, and they are not the same team without those two. Nick Beal and Budge Pountney are also players that can change a game but without Cohen and Dawson I feel they play at around 60% of their potential.
"With a full team, I greatly admire Northampton because they are a complete outfit. They play a very quick game and they have an excellent back line. I think they have progressed since they came to Biarritz in Round 1. However, it is true that Dawson is a key element in their game and, without him, they lack speed - he creates so much.
"We expect a hostile welcome from a good crowd at Northampton. Wayne Smith has done extremely well since his arrival, especially in strengthening his squad by recruiting some key southern hemisphere players.
"This is our biggest match in the Heineken Cup so far, which is why it is an exciting prospect. It is so much more of a challenge when you have to take risks.
"We did some opposition training on Saturday and a few players took part in a local under-23 game but we have had no match practice since before Christmas. Northampton may be tiring after a large number of matches but we run the risk of lacking competition at this stage."