Ulster's win over Glasgow last weekend, combined with their better head-to-head record against the Saints, means that the Irish province has guaranteed their place in the knockout stages as pool winners. But there are a host of teams in with a shout of getting through as either of the two best-placed runners-up.
It is highly likely that one of the best placed runners-up will come from Pool Six, where Toulon have accrued enough points to guarantee their place in the quarter finals even if they are beaten in Montpellier on Saturday afternoon. Montpellier themselves have already got 18 points, currently the highest of any second-placed teams.
Pool One is still up for grabs, with Saracens (18 points) and Munster (15 points) battling it out for top spot. Both teams are at home on Sunday to the already-eliminated Edinburgh and Racing Metro respectively. It is a similar situation in Pool Two, where Toulouse (18 points) travel to Leicester (16 points) for a winner-takes-all clash on Sunday. If Leicester beat the French giants and Munster overcome Racing then the Tigers will be through and Toulouse eliminated.
Leinster are another European powerhouse in danger of going out of the competition. Clermont Auvergne's unbeaten run in Pool Five has seen them all but guarantee a home quarter final, something they will confirm with a win over the Scarlets in Llanelli on Saturday evening. Leinster's 15 points sees them in the mix for a possible seventh or eighth seeding place, but they face a tricky trip to Exeter's Sandy Park on Saturday evening and like the Saints they will need other results to go their way.
Finally, although Pool Three has already been decided - Harlequins' win over Connacht last weekend having booked their place in the knockouts - Biarritz's 14 points and impressive try record means that a bonus point win over the Londoners on Friday night will also put them into the mix. However Quins will still be looking for a home knockout tie and their defence has been breached just six times in the five matches.
Rankings are decided as follows - 1) league points accrued during pool stages; 2) number of tries scored in pool stages; 3) aggregate points difference; 4) fewest number of players sent off and/or suspended during pool stages; 5) toss of a coin.
As seems to be the case with every final round of pool matches there will be calculations aplenty being made throughout the weekend!
But as already mentioned, Saints' task is simple - win! It will not be easy, though, at a venue which will be new to all of the travelling players and supporters. Scotstoun has been the Warriors' training base since 2009 and began hosting matches in 2012. It has a capacity just shy of 10,000 and was used to host the Scotland leg of the 2012 IRB World Sevens Series.
Saints last visited Glasgow in October 2004, when a try in the third minute by Ben Cohen and eight points from Shane Drahm's boot overcame the Warriors in soggy conditions at Hughenden.