Castres are only three points behind Ulster but are only two points ahead of Ulster in the Pool. A win for the French side over Saints would pile the pressure on the Pro12 leaders ahead of the final round of the Pool stage.

Ulster would have to travel to France for the final Pool game knowing they needed a victory in Castres to secure their own quarter-final place. Saints know if they win this game, they are still in the hunt for a place in the knockout stages.

The English side, who have won three of the previous four meetings with the French side, would then have to travel to Glasgow needing a victory to qualify for the last eight of the tournament.

Ulster, Castres and Northampton have it all to play for in this round of games but the England versus France clash in the midlands could see one of those clubs European campaign come to an end.

Match Facts

The English side have won three of the five meetings between these teams in the Heineken Cup but were on the wrong end of a 21-16 scoreline in the reverse meeting between the two earlier this season.

The aggregate score in the history of this Heineken Cup fixture is 124-88 in favour of the Saints, with almost half of Castres' points coming in a 41-22 victory last season.

Castres' success rate at the scrum is superior to any other side in the tournament (97%).

Should Northampton secure victory against Castres, it would move their all-time record against French opponents to P26 W13 L13.

Castres have won just four of 27 matches on the road in the Heineken Cup, with just one of these coming against an English side (2001 v Harlequins).