The five Pool winners in the Amlin Challenge Cup earn quarter-final places, and going into the final round, the winners of all five Pools have yet to be decided. The final three places in the knockout stages are filled by the third, fourth and fifth best Pool runners-up from the Heineken Cup.
Only Munster and reigning champions Leinster are so far guaranteed Heineken Cup quarter-final tickets, so there will be the usual number of twists and turns to come in the over the next few days.
There will also be plenty of drama from Thursday onwards in the Amlin Challenge Cup with two clubs in each of the five Pools still in contention for top spot. The most dramatic weekend of action in European rugby will kick-off at Edgeley Park on Thursday night when two-time tournament winners Sale Sharks host former Heineken Cup holders Brive.
That will be the first of 22 fixtures across the two tournaments that will determine which 16 clubs move forward to chase the top two titles in northern hemisphere club rugby.
As well as Toulouse, two more Heineken Cup winners, Ulster Rugby (1999) and Leicester Tigers (2001, 2002), as well as the Ospreys, could conceivably make their Amlin Challenge Cup debuts depending on results.
"Since we launched the system of three Heineken Cup runners-up joining the Amlin Challenge Cup Pool winners in the quarter-finals the quality has certainly risen. To add to that, the winners of the Amlin Challenge Cup are assured of a place in next season's Heineken Cup," said ERC Chief Executive, Derek McGrath.