By Tadhg Peavoy

Joe Schmidt’s selection of Jonathan Sexton and Ian Madigan in the Leinster starting XV is what all rugby fans wanted to see.

Madigan has set the Leinster team alight since Sexton’s enforced injury absence and the youngster may be disappointed not to get the nod at No 10 over his teammate, who returned from injury last week in Leinster’s 41-22 mauling of Zebre.

But Schmidt has opted for the experience of age with Sexton at outhalf, instead opting to use Madigan’s unpredictability in the centre slot – a place where he looked very dangerous against Italy in the Six Nations.

With Brian O’Driscoll outside Madigan, and Sexton inside him, the young tyro should be well marshalled and his 10-13 teammates will hopefully coax a very balanced performance from him.

In terms of personnel for this encounter, bar Gordon D’Arcy’s absence due to a calf strain, the 23 is massively strong.

The back three of Rob Kearney, Fergus McFadden and Isa Nacewa shows both huge experience, as well as a youthful exuberance.

Having Richardt Strauss fit to play hooker is a major boon for Leinster; he is the best lineout thrower at the province and his dynamism around the park adds the dimension of a fourth ball-handling back-rower.

The visitors to the RDS also boast talent throughout their XV. Their backline in particular has plenty of names to trouble the Leinster backroom team. Puma Marcelo Bosch at 15, Les Bleus duo Damien Traille and Benoit Baby in the centres, and US Eagle Takudzwa Ngwenya on the wing, being serious threats.

And then there is No 9. Isaac Boss has done superbly well since becoming Leinster’s week-in, week-out scrumhalf following Eoin Reddan’s broken leg, but he faces a massive challenge in taking on Dimitri Yachvili on Saturday.

Yavhvili’s passing and kicking game is unrivalled in Europe, and if his pack gives him the opportunity, he will unleash the backline with great vengeance and furious anger.

On paper, Leinster’s pack should have the upper hand. Journeyman loosehead Thomas Synaeghal and looshead playing tighthead Ben Broster should struggle against Cian Healy and Mike Ross; if they do, Biarritz will too, with a soft scrum that yields penalties early on.

From No 5-8, Biarritz have a brawn overload; the engine room comprises two 6ft 8” beasts in Erik Lund and Pelu Ian Taele. While flankers Thibault Dubarry and Raphael Lakafia are the definition of aggressive. Combined, they command a weight advantage of 7kg and a height advantage of four inches over Kevin McLaughlin and Shane Jennings.

While at No 8, Imanol Harinordoquy needs no introduction: a supreme ball-handling No 8.

The challenge of Jamie Heaslip is to nullify Harinordoquy’s creativity and driving runs, while McLaughlin and Jennings use superior speed and breakdown ability to deprive Dubarry and Lakafia of possession.

In the Top 14, Biarritz have struggled this term. With one game left in the season, they lie 11th in the table and will mark down 2012/13 as a league season to forget.

Even in Heineken Cup Pool 3 – from which they qualified for the Amlin Challenge Cup - they struggled, losing home and away to Harlequins and away to Connacht.

However, a fine 41-31 away win over Gloucester at Kingsholm in the Amlin quarters set out their stall to retain the title they won in 2012. Their low league position also means that their only chance of qualifying for the Heineken Cup for next season comes from winning the Amlin this season.

But Leinster also have plenty to play for. Schmidt’s every move this weekend is being analysed as the IRFU make a final call on who will become the next Ireland head coach, and he will be intent on getting every ounce from his team.

The other added incentive for Leinster is the fact no Irish team have won this competition, and securing the silverware at a home final in the RDS on 17 May would be an achievement they don’t want to miss out on. Add in the fact the British and Irish Lions squad is being named on Tuesday, and there is much more than meets the eye to this tie.

Home advantage for Leinster is huge, and stereotypically Biarritz have tended to struggle away from home.

Yachvili this week pointed out Sexton as the danger man, but really that is just pre-match guff. Biarritz know well that Leinster have a unique ability – much like Clermont – to strike from anywhere from No 9 to 15, and will be prepared for that.

Yachvili also said: "We can play without pressure, just play our rugby.” And that is the key for his team: nobody expects them to win, so they can go out there and feel very little burden of expectation upon their shoulders; they can relish being underdogs.

All the variables taken into account, this should prove to be a very tight game; Leinster are very adept at winning very tight games.

Verdict: Leinster by six.

Leinster v Biarritz, Amlin Challenge Cup semi-final at the RDS, Saturday 27 April, kick-off 1430:

Leinster XV: 15 Rob Kearney 14 Fergus McFadden 13 Brian O'Driscoll 12 Ian Madigan 11 Isa Nacewa 10 Johnny Sexton 9 Isaac Boss 1 Cian Healy 2 Richardt Strauss 3 Mike Ross 4 Leo Cullen, 5 Devin Toner 6 Kevin McLaughlin 7 Shane Jennings 8 Jamie Heaslip.
Replacements: 16 Sean Cronin 17 Jack McGrath 18 Jamie Hagan 19 Quinn Roux 20 Rhys Ruddock 21 John Cooney 22 Andrew Goodman 23. Andrew Conway.

Biarritz XV: 15 Marcelo Bosch 14 Taku Ngwenya 13 Benoît Baby 12 Damien Traille 11 Aled Brew 10. Jean-Pascal Barraque 9 Dimitri Yachvili 1 Thomas Synaeghel 2 Arnaud Heguy 3 Ben Broster 4 Erik Lund 5 Pelu Taele 6 Thibault Dubarry 7 Raphael Lakafia 8 Imanol Harinordoquy.
Replacements: 16 Benoit August 17 Eugène Van Staden 18 Francisco Gomez Kodela 19 Mathias Marie 20 Wenceslas Lauret 21 Yann Lesgourgues 22 Seremaïa Burotu 23 Teddy Thomas.