Harlequins director of rugby Dean Richards is hoping his side has shed enough of its 'Heineken Cup naivety' by the time they play in the quarter-finals.
Magners League champions Leinster face a trip to London to face the top English qualifiers for the last eight and Richards has already established the Dubliners as favourites.
"Leinster will certainly start as favourites. With stars like Brian O'Driscoll in their ranks they are a quality outfit," said Richards.
"We have nothing to lose because there were little or no expectations on us at the start of the campaign. We are maturing, and becoming a difficult side to beat, and our naivety is dropping off game by game.
"Last season we didn't win a game in the Heineken Cup, but the experience we gained during that campaign helped us this season. Even though we only managed a draw in our six games, we were heartened by some of the performances.
"This season we have played in front of 80,000 fans in Paris, beaten Stade Français twice and gone on to win our Pool and cinch a home quarter-final.
"Now we have to step up a gear if we are to go any further. We are only looking as far as the quarter-finals at this stage and there is huge excitement about the challenge we face. We are talking about perhaps switching the game to Twickenham because we got 50,000 people there the last time we played.
"I love this competition. If you win the Heineken Cup you are right at the top of the tree in the northern hemisphere."
Finals Edition: Listen to the best guide to the European Rugby Cup Finals weekend in Dublin, which sees Leinster Rugby take on Stade Francais Paris at the RDS on Friday night in the Amlin Challenge Cup Final and then ASM Clermont Auvergne tackle Toulon in an all-French affair at the Aviva Stadium on Saturday.