And the old record will also be overtaken at the new Aviva Stadium when Leicester Tigers return to the Irish capital for a 2009 Heineken Cup final re-match with Leinster. A full-house of 51,700 is expected at the Aviva.
The sold-out signs have been up for a while at both Estadio Anoeta, where Biarritz Olympique will face Toulouse in a re-run of last year's final on Sunday, and at stadium:mk in Milton Keynes for the Anglo-Irish contest between top seeds Northampton Saints and Ulster Rugby.
It means there could be almost 160,000 fans going through the turnstiles in three countries - a figure second only to the tournament high of 162,500 that attended the quarter-final matches in 2005.
The 2011 Heineken Cup quarter-finals, venues and capacities are:
Perpignan v Toulon - Olympic Stadium, Barcelona - 55,000
Leinster v Leicester Tigers - Aviva Stadium, Dublin - 51,700
Northampton Saints v Ulster Rugby - stadium:mk, Milton Keynes - 21,500
Biarritz Olympique v Toulouse - Estadio Anoeta, San Sebastian - 32,000
Northampton Saints might not like to be reminded of this but no team that has qualified for the Heineken Cup quarter-finals as the No 1 seeds has gone on to win the title. Since the introduction of the home and away format in the 1997/98 season, only two of the 13 top seeded teams have reached the final - Stade Français Paris in 2001 and Toulouse in 2004.
Five of the others fell at the first knock-out hurdle and six in the semi-finals. And while none of the No 1 seeds, including the eight who came through the Pool stages with six from six, have gone on to Heineken Cup glory, teams seeded as low as No 6 - Munster in 2008 and Leinster a year later - have lifted the silverware.
Ian Humphreys will be hoping to match the achievements of elder brother David by taking Ulster to a Heineken Cup final. David was captain of Ulster back in 1999 when they won the title at Lansdowne Road. But Ian has already experienced a Heineken Cup final having come on as a replacement for Andy Goode in the 62nd minute of Leicester Tigers 2007 defeat to London Wasps.
There were three other Irish players involved in that final at Twickenham who are still in the hunt for more glory this season. Leo Cullen and Shane Jennings were in the Leicester Tigers side, while Eoin Reddan was a try scorer for London Wasps. All three are in the Leinster squad preparing to face the Tigers on Saturday.
The grand old man of the Heineken Cup Cedric Heymans - who made his debut for Brive against Neath on 12 October, 1996 - will be chasing a fifth Heineken Cup winners medal with Toulouse in the knock-out stages of the 2010/11 tournament.
The French international wing is also one of only three players to have won the title with more than one club. An unused replacement in the 1997 Heineken Cup final with Brive, he then played in the winning Toulouse teams of 2003, 2005 and 2010. Leinster scrum half Eoin Reddan will be looking to join the list of double winners having played for London Wasps in their 2007 triumph over Leicester Tigers at Twickenham Stadium.
The full list of winners from two clubs is:
Philippe Carbonneau - Toulouse 1996, Brive 1997
Cedric Heymans - Brive 1997, Toulouse 2003, 2005, 2010
Federico Mendez - Bath 1998, Northampton Saints 2000
Biarritz Olympique prop Sylvain Marconnet will be hoping to make it third time lucky this season in the Heineken Cup after twice falling at the final hurdle in the past. France's most capped prop was a loser with Stade Français Paris in the 2001 and 2003 Heineken Cup finals.
Toulouse prop Census Johnston knows all about the atmosphere at Estadio Anoeta. He helped Biarritz Olympique beat both Sale Sharks and Bath over the Spanish border in their march to the 2006 Heineken Cup final. That mission ended in disappointment in Cardiff with defeat at the hands of Munster, but since then the Samoan giant has tasted success with Toulouse in last year's final at Stade de France.
No side has played against Leicester Tigers more times in the Heineken Cup than Leinster - and no team has beaten the Tigers more than the Irish province. So something will have to give when the perfectly balanced record of five wins apiece from 10 European clashes goes on the line at the Aviva Stadium on Saturday.
Richard Cockerill was in on the ground floor of the great Euro rivalry between the two sides, making his Heineken Cup debut at Lansdowne Road on the night Leicester made their bow in the tournament on Wednesday, 16 October, 1996. The visitors triumphed 27-10, with another Front Row Union member Graham Rowntree scoring the Tigers' first try, to notch the first of their two wins over Leinster in Dublin. But in seven games against the same opposition, five with Tigers and two with Montferrand, Cockerill has lost four and won only three.
Flying Biarritz back Iain Balshaw made his Heineken Cup debut for Bath against Brive as an 18-year-old on 5 October, 1997. His debut came in the season Bath became the first non-French champions, although his replacement appearance at Stade Municipal in a 27-12 defeat was his only one of that campaign. Balshaw will turn 32 next week and is seeking to avenge Biarrtiz Olympique's final defeat by Toulouse last season in Sunday's quarter-final.
Meanwhile, Balshaw's Biarritz team-mate Dimitri Yachvili needs 18 points to become only the fourth player in Heineken Cup history to score 600 points.
Northampton Saints No 8 Roger Wilson will be playing against many of his former Ulster team-mates when he lines-up in Sunday's quarter-final at Milton Keynes. Wilson has not missed a Heineken Cup game for Saints this season and has 10 wins from 13 games. That compares very favourably to his record of 12 wins in 26 outings for Ulster.
Perpignan lock Rimas Alvarez Kairelis is on the verge of making history by becoming the first Argentinian player to qualify for an ERC Elite 50 cap award. The long serving forward made his Perpignan debut against Amatori & Calvisano back in the 2001/02 Pool stages and was in the side that went to Dublin for the 2003 Heineken Cup final. If he appears in the quarter-final against Toulon it will be his 50th appearance for his club in the tournament.