Defeat by Leinster Lions at Lansdowne Road in Round 1 means Biarritz believe they need a 10-points haul over the next two weekends to keep their automatic quarter-final qualifying hopes alive.
'We don't have any choice," said Biarritz coach Patrice Lagisquet. "If we want to compete with Leinster for the top spot in this Pool, we have to aim to win both of these matches against Cardiff Blues and pick up a bonus point each time.
'We know it's going to be difficult because Cardiff Blues have a more complete, solid side this year.
"We won't for one minute think there will be a re-run of our 75-25 victory last season - Cardiff are far too proud for that. They will be out to try to avenge that defeat and we will have to be on guard.
"From their Heineken Cup performances so far this season - they almost beat Sale Sharks and their match against Leinster was tight - they will be more aggressive and altogether a tougher proposition this time around.
'However, we have had a good Christmas run in the French Championship, and we have been boosted by the return of three key players - Serge Betsen, Thomas Lià¨vremont and Jack Isaac," said Lagisquet.
"They have transformed the face of Biarritz Olympique since their return. Serge had great games in the wins over Montpellier and Toulouse and Thomas and Jack are in great form since their recovery from medium-term injuries.
"Lià¨vremont was out for nine weeks after tearing a thigh muscle against Narbonne and Jack had a number of injuries culminating in a broken hand.
'We are not 100% yet but things are getting better all the time. We are pleased to restart our Heineken Cup campaign at home - we have scored more than 30 points in all our home matches so far and we want to continue with that form.'