O'Brien blow puts pressure on new generation of Blues
Leinster are back where they feel they belong, but when Leo Cullen looks around the dressing-room before kick-off in Lyon tomorrow he won't see many battle-hardened looks in the eyes.
On Wednesday, he lost Cian Healy's impact off the bench and yesterday Seán O'Brien was taken from the back-row with a hamstring problem. With senior men like Jamie Heaslip and Rob Kearney already sidelined, it could prove a blow too many.
The decision to recall Fergus McFadden ahead of Adam Byrne is a nod to the lack of experience across the board. Not many of the team that takes the field against Clermont Auvergne have experienced this stage before, but they were raised on the province competing on these occasions and expect to perform. It's up to the new generation to show they are capable of living in this company.
The biggest concern for Stuart Lancaster, Leo Cullen and their players is the fact that the Blues' worst performances this season have been reserved for their visits to France. In defeat to Montpellier and when drawing against Castres, they struggled with the power. Tomorrow, they will step up in class again to face a team who can mix it in the power stakes but add an extra dimension in the backs.
All year, Leinster have been learning and adapting. Their quarter-final win over Wasps was their most impressive outing to date and showed how far they have come since Lancaster came on board.
Their youthful team lacks in experience, but remains committed to having a go. They are enjoying the way the former England coach wants them to play, while the intensity of the training sessions should stand them in good stead.
The key to beating Clermont is staying in the fight and trusting your fitness. The capacity of the French side to pummel teams with relentless waves of powerful attack is well known, but if you can live with their big moments and surf your way past the swell then they wilt and you can take advantage.
Years of close calls have left them scarred and Leinster will hope to take them to the places they don't enjoy going. Down the stretch, the mental battle will be there for the province to win. The difficult part is surviving the storm, of coping with the power game and remaining disciplined enough to prevent Clermont from gaining momentum.
It is about getting your hands on the ball and providing front-foot ball for Garry Ringrose and Joey Carbery to create. It's about giving the first-time semi-finalists like Tadhg Furlong, Dan Leavy, Jack Conan, Luke McGrath and Robbie Henshaw confidence. Some of those players now have a body of international work behind them, but this is a different experience.
The Six Nations crowds don't create the kind of intimidating noise levels that Clermont's loyal yellow army will generate.
That's where Richardt Strauss, Jack McGrath, Devin Toner, Isa Nacewa and Johnny Sexton come in. They have experienced an away semi-final in France before and their calm will be needed.
Clermont are still good to watch, but are they the force of old? Their backline that has been robbed of the talents of Noa Nakataici, Isaia Toeava and Wesley Fofana, but they can still name the dangerous Remi Lamerat alongside Aurelien Rougerie in midfield, while Nick Abendanon is dangerous out wide and Camille Lopez and Morgan Parra are formidable half-backs.
Up front, they have the grit to win in the tight and the ball-carriers to get over the gainline regularly if Leinster allow them. Lock Sebastien Vahaamahina is a danger with ball in hand who can release runners on his shoulder.
In 2012, Joe Schmidt's side played brilliantly and still needed a heroic Gordon D'Arcy tackle to get over the line. It is unlikely to be much easier this time and the experience levels are much lower but the confidence levels are high.
Lancaster's heads-up game-plan and the creative combination of Sexton, Ringrose and Carbery combined with Henshaw's direct approach can cause the French side problems but when the game is in the melting pot their lack of experience may tell. The loss of O'Brien tips the balance.