Glasgow Warriors' hopes of a Heineken Cup quarter-final spot are hanging by a thread but their French visitors, Castres Olympique, have a slim chance of qualification for the last eight.
Ulster Rugby are in the driving seat in Pool 4, with only Northampton Saints standing between them and a quarter-final place.
The Scottish outfit, for whom the form of Henry Pyrgos has been a bonus, have endured a miserable start to their campaign so far, having failed to win a single game, and have failed to win one of their last five games in the Heineken Cup.
Glasgow only have a 25 percent success rate against French opponents, winning six, drawing two and losing 16 of their games against French clubs in the Heineken Cup.
Castres have not done much better but their last outing saw them record a 21-16 victory over Northampton Saints to end their four-match losing streak in the tournament.
Match Facts
• Against French opposition, Glasgow have a 25% win rate. They have won six, lost 16 and drawn twice against French sides in the Heineken Cup.
• Glasgow have failed to win any of their last five Heineken Cup matches, losing four and drawing one.
• Glasgow have a goal kicking success rate of 43%, lower than any other team in the tournament this season.
• Castres have suffered defeat in nine of their last 11 Heineken Cup matches, but ended a four-match losing streak with a win over Northampton in round two of the pool stages.