Toulouse, the four-time Heineken Cup champions, are bidding to reach the knock-out stages for a record 15th time and Munster for the 14th time.
The knock-out stage appearances so far (excluding the 1997/98 quarter-final play-offs) are:
14 - Toulouse
13 - Munster
10 - Leicester Tigers, Leinster
8 - Biarritz Olympique, Cardiff Blues, Stade Francais Paris
7 - Scarlets
5 - Bath Rugby, Perpignan, Northampton Saints
4 - ASM Clermont Auvergne, London Wasps
3 - Gloucester Rugby, Harlequins, Ospreys, Ulster Rugby, Saracens
2 - Edinburgh Rugby, Brive, Pau, Swansea
1 - Dax, Pontypridd, Colomiers, Newcastle Falcons, Castres Olympique, London Irish, Sale Sharks, Toulon
… and the best runners-up
The format of the two best Heineken Cup runners-up qualifying for the quarter-finals as the No 7 and No 8 ranked clubs has been in operation since the 1999/00 season - with bonus points coming into the equation in season 2003/04.
Here are some quarter-final qualification pointers since those changes came into place:
* No club has qualified as a Pool winner on less than four wins.
* No club has qualified as a Pool winner on less than 17 points. Toulon topped Pool 3 with 17 points in 2010/11.
* No club has qualified as one of the best runners-up on less than four wins or 19 points although in 2003/04, Celtic Warriors, and in 2006/07, the Ospreys, both discovered that even 20 points was not sufficient to make the knock-out stages. Leicester Tigers in 2004/05 and Northampton Saints in 2009/10 qualified as one of the best runners-up on 19 points.