LEINSTER: Coach Michael Cheika Captain Leo Cullen Key player: Brian O'Driscoll HC pedigree: Winners 2009

LONDON IRISH: Coach Toby Booth Captain Bob Casey Key player: Paul Hodgson HC pedigree: Semi-finals 2008

SCARLETS: Coach Nigel Davies Captain Mark Jones Key player: Stephen Jones HC pedigree: Semi-finals 2000, 2002, 2007

BRIVE: Coach Christophe Lassucq Captain Alix Popham Player to watch: Riki Flutey HC pedigree: Winners 1997

Champions Leinster, despite the loss of the talismanic Rocky Elsom, have started the season at a gallop and look well placed to launch a strong defence of their title.

The addition of lock Nathan Hines and prop Mike Ross provides extra depth and class up front while a razor-sharp Brian O'Driscoll spearheads a backline to die for.

But they face a strong challenge from free-scoring London Irish, who have shown that when they get on top of teams an attacking bonus point usually follows.

The Scarlets, the lone Welsh standard-bearers in Europe for so long, look short of the necessary firepower to revive former glories in the face of such opposition.

Brive will be no pushovers and have plenty of familiar faces with their sizeable English contingent, but the 1997 champions look set for also-ran status in a tough group.