Heineken Cup pool-by-pool guide

The 17th season of Europe's most prestigious club competition returns on Friday. Once again there are 24 teams - seven English, six French, four Irish, three Welsh, two Scottish and two Italian - divided into six pools of four.

The six group winners will all progress to the quarter-finals, plus the two best runners-up. We assess the prospects for each pool.

Pool 1:

Two-time champions Munster played three fiercely contested matches against last-year's beaten finalists Northampton in the 2009-10 tournament - a win apiece in the pool stages, with Munster winning a quarter-final clash - and the two teams will be favourites to progress from a fiercely contested pool. But Welsh region the Scarlets - with Wales' World Cup fly-half Rhys Priestland back in harness - are an emerging force and Castres wll be strong at home.

Castres

Chris Masoe

Heineken Cup pedigree - last year: 3rd in Pool 1, best: semi-finals in 01-02

Star player: Back-rower Chris Masoe

Coach: Laurent Labit and Laurent Travers

Position in Top 14 in 2010/11: 3rd. Current: 3rd

Munster

Paul O'Connell

Heineken Cup pedigree - last year: 2nd in Pool 3, best: champions in 05-06 and 07-08

Star player: Lock Paul O'Connell

Coach: Tony McGahan

Position in Celtic League in 2010/11: 1st. Current: 3rd

Northampton

Ben Foden

Heineken Cup pedigree - last year: runners-up, best: champions in 99/00

Star player: Full-back Ben Foden

Coach: Jim Mallinder

Position in Premiership in 2010/11: 4th. Current: 6th

Scarlets

Rhys Priestland

Heineken Cup pedigree - last year: third in Pool 5, best: semi-finals in 99-00, 01-02 and 06-07

Star player: Fly-half Rhys Priestland

Coach: Nigel Davies

Position in Celtic League in 2010/11: 5th. Current: 8th

Pool 2:

The Blues missed out on the final after an agonising semi-final defeat on penalty kicks in 2009, and became the first Welsh team to win a European trophy when they beat Toulon to claim the second-tier Challenge Cup the following year. With their Wales World Cup stars back, they are slight favourites but this is likely to be another close group. Edinburgh are the outsiders, but London Irish - semi-finalists in 2008 - and cash-rich Racing Metro are both likely to challenge.

Cardiff Blues

Jamie Roberts

Heineken Cup pedigree - last year: second in Pool 1, best: runners-up in 95-96

Star player: Centre Jamie Roberts

Coach: Justin Burnell and Gareth Baber

Position in Celtic League in 2010/11: 6th. Current: 5th

Edinburgh

Edinburgh's Mike Blair

Heineken Cup pedigree - last year: fourth in Pool 1, best: quarter-finals in 03-04

Star player: Scrum-half Mike Blair

Coach: Michael Bradley

Position in Celtic League in 2010/11: 8th. Current: 10th

London Irish

Delon Armitage

Heineken Cup pedigree - last year: fourth in Pool 3, best: semi-finals in 07-08

Star player: Full-back Delon Armitage

Coach: Toby Booth

Position in Premiership in 2010/11: 6th. Current: 3rd

Racing Metro

Sebastien Chabal

Heineken Cup pedigree - last year: third in Pool 2, best: third in Pool 2 10-11

Star player: Number eight/lock Sebastien Chabal

Coach: Pierre Berbizier

Position in domestic league in 2010/11: 2nd. Current: 5th

Pool 3:

Leinster, twice champions in the last three years, will be expected to top the pool even without their talismanic captain Brian O'Driscoll, who will be sidelined until the knock-out stages. They may lose a game or two on the way, with no easy away trips. The other three teams are reasonably evenly matched. Bath have a proud European pedigree but have been too inconsistent, Glasgow are good at one-off wins but lack depth, while Montpellier make their Heineken debut.

Bath

Stephen Donald

Heineken Cup pedigree - last year: third in Pool 4, best: champions in 97-98

Star player: Fly-half Stephen Donald

Coach: Ian McGeechan

Position in Premiership in 2010/11: 5th. Current: 7th

Glasgow

Richie Gray

Heineken Cup pedigree - last year: third in Pool 6, best: quarter-final play-off in 97-98

Star player: Lock Richie Gray

Coach: Sean Lineen

Position in Celtic League in 2010/11: 11th. Current: 4th

Leinster:

Sean O'Brien

Heineken Cup pedigree - last year: champions, best: champions 08-09 and 10-11

Star player: Flanker Sean O'Brien

Coach: Joe Schmidt

Position in Celtic League in 2010/11: 2nd. Current: 2nd

Montpellier:

Francois Trinh-Duc

Heineken Cup pedigree - debut in Heineken Cup, last year: Challenge Cup

Star player: Fly-half Francois Trinh-Duc

Coach: Fabien Galthie

Position in Top 14 in 2010/11: 6th. Current: 12th

Pool 4:

With Aironi the weakest team in the competition, two teams could progress from this pool if they claim two bonus-point wins against the Italians. Two-time champions Leicester have the pedigree if not the current form, struggling as they are domestically and with myriad injuries. They may have to play second fiddle to Clermont, who have powerful strength in depth. Ulster, never to be under-estimated at Ravenhill, will do well to match last year's quarter-final spot.

Aironi

Marco Bortolami

Heineken Cup pedigree - last year: fourth in Pool 4, best: fourth in Pool 4 10-11

Star player: Lock Marco Bortolami

Coach: Rowland Phillips

Position in Celtic League in 2010/11: 12th. Current: 12th

Clermont Auvergne

Morgan Parra

Heineken Cup pedigree - last year: second in Pool 2, best: quarter-finals in 99-00, 01-02 and 09-10

Star player: Scrum-half Morgan Parra

Coach: Vern Cotter

Position in Top 14 in 2010/11: 5th. Current: 2nd

Leicester

Manu Tuilagi

Heineken Cup pedigree - last year: quarter-finals, best: champions 00-01 and 01-02

Star player: Centre Manu Tuilagi

Coach: Richard Cockerill

Position in Premiership in 2010/11: 1st. Current: 10th

Ulster

Ruan Pienaar

Heineken Cup pedigree - last year: quarter-finals, best: champions 98-99

Star player: Scrum-half Ruan Pienaar

Coach: Brian McLaughlin

Position in Celtic League in 2010/11: 3rd. Current: 7th

Pool 5:

Treviso are an improving force in the Pro12 (Celtic) League and may manage a couple of wins but are not yet realistic contenders. Biarritz, twice runners-up, are bottom of the Top 14 but usually raise their game in Europe, with Imanol Harinordoquy an inspirational force. But this group represents an opportunity for English champions Saracens, while the Ospreys, despite losing several big names, also have high hopes of getting beyond the quarter-finals for the first time.

Benetton Treviso:

Alessandro Zanni

Heineken Cup pedigree - last year: fourth in Pool 5, best: second in group in 95-96

Star player: Flanker Alessandro Zanni

Coach: Franco Smith

Position in Celtic League in 2010/11: 10th. Current: 6th

Biarritz:

Taku Ngwenya

Heineken Cup pedigree - last year: quarter-finals, best: runners-up in 05-06 and 09-10

Star player: Wing Taku Ngwenya

Coach: Serge Mihas and John Isaac

Position in Top 14 in 2010/11: 5th. Current: 14th

Ospreys:

Shane Williams

Heineken Cup pedigree - last year: third in Pool 3, best: quarter-finals in 07-08, 08-09 and 09-10

Star player: Wing Shane Williams

Coach: Sean Holley and Jon Humphries

Position in Celtic League in 2010/11: 4th. Current: 1st

Saracens:

Schalk Brits

Heineken Cup pedigree - last year: fourth in Pool 2, best: semi-finals in 07-08

Star player: Hooker Schalk Brits

Coach: Mark McCall and Andy Farrell

Position in Premiership in 2010/11: 2nd. Current: 2nd

Pool 6:

Harlequins, having won all 10 games this season, are the form side but will probably have to beat four-time champions Toulouse at least once to top the pool, no easy feat. The French aristocrats lead the Top 14 but face two very testing games at The Stoop and Kingsholm, a fortress for Gloucester. Irish province Connacht are likely to find the going very tough on their first entry into the elite competition, despite reaching the semi-finals of the Challenge Cup three times.

Connacht:

Henry Fa'afili

Heineken Cup pedigree - debut in Heineken Cup, last year: Challenge Cup

Star player: Centre Henry Fa'afili

Coach: Eric Elwood

Position in Celtic League in 2010/11: 9th. Current: 9th

Gloucester:

James Simpson-Daniel

Heineken Cup pedigree - last year: Challenge Cup best: semi-finals 00-01

Star player: Wing James Simpson-Daniel

Coach: Bryan Redpath

Position in Premiership in 2010/11: 3rd. Current: 4th

Harlequins:

Chris Robshaw

Heineken Cup pedigree - last year: Challenge Cup best: quarter-finals 96-97, 97-98 and 08-09

Star player: Chris Robshaw

Coach: John Kingston

Position in Premiership in 2010/11: 7th. Current: 1st

Toulouse:

Thierry Dusautoir

Heineken Cup pedigree - last year: semi-finals best: champions 95-96, 02-03, 04-05 and 09-10

Star player: Thierry Dusautoir

Coach: Yannick Bru and Jean-Baptiste Elissalde

Position in Top 14 in 2010/11: 1st. Current: 1st

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