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Cian Murtagh
BBC Sport NI at Dublin's Aviva Stadium

There is a huge contingent of Ulster fans at the Aviva Stadium and on the streets of Dublin today.

Ulster estimated a travelling support of 15,000 but it feels like much more than that and every support seems to have been equipped with a flag – it’s an incredible sight.

Dry and mild evening in Dublin with a hint of a breeze – just about perfect.

Ulster are waiting for their opponents in the tunnel, Rory Best rolling his neck and popping his eyes to pass the time.

Leinster arrive and the two teams head out into the cauldron...

Ulster head coach Dan McFarland speaking on BT Sport:

"One of the key battle grounds will be the speed of their ball. How we go about slowing that down remains to be seen.

"Leinster’s ruck success rate is top of everybody in this competition so it’s easier said than done."

There are over 40,000 people in the Aviva Stadium for this one and the atmosphere is bubbling.

The winners today will face either Racing 92 or Toulouse in the last four.

Cian Murtagh
BBC Sport NI at Dublin's Aviva Stadium

Image source, Getty Images

How might Ireland’s disappointing Six Nations campaign influence today’s game?

Leinster, as the bulk providers to the national squad, have not been able to call on many of their front-line players since mid-January and they suffered last week when a second-string team lost to Edinburgh in the Pro14.

The likes of James Ryan, Tadhg Furlong, Sean O’Brien and Cian Healy will all be making their first appearances since Ireland’s loss to Wales in Cardiff while

Ulster have less international players to weave back into their senior panel but the return of Rory Best, Iain Henderson and Jacob Stockdale represents a significant boost.

And what about Sean Cronin? The Leinster hooker is the joint top try scorer in Europe this season but he was hauled off after 50 minutes of Ireland’s win over Italy in Rome – he might want to show watching Ireland coach Joe Schmidt what he can do today.

Cian Murtagh
BBC Sport NI at Dublin's Aviva Stadium

Image source, Getty Images

There are seven ex-Leinster players in Ulster's match squad, which could have an impact.

Second row Ian Nagle, on loan from Leinster this year, is not in the Ulster panel today but speaking to him earlier he insists that familiarity will make little difference in terms of tactics and set-pieces.

But try telling that to the likes of Jordi Murphy, playing against Leinster for the first time since winning the European title with them last summer, or John Cooley or Marty Moore - all three will be desperate to prove a point.

This could be tasty.

Image source, getty

Second row Iain Henderson has been passed fit to play for Ulster.

Henderson has overcome a knee problem, with fellow injury doubts Darren Cave and Marty Moore also named in the starting line-up for Saturday's game.

Michael Lowry plays at full-back, with internationals Jacob Stockdale, Rory Best and Jordi Murphy all returning.

Ulster:M Lowry; R Baloucoune, D Cave, S McCloskey, J Stockdale; B Burns, J Cooney; E O'Sullivan, R Best (capt), M Moore; I Henderson, K Treadwell; N Timoney, J Murphy, M Coetzee.

Replacements:R Herring, A Warwick, W Herbst, A O'Connor, S Reidy, D Shanahan, L Marshall, A Kernohan.

Image source, Getty Images

In Sexton's absence, Ross Byrne starts for Leinster at fly-half, but Rob Kearney is on the bench.

Kearney's absence from the starting team sees Jordan Larmour preferred at full-back, with Adam Byrne and Dave Kearney on the wings for the Dublin clash.

James Lowe is not included in the match-day squad as the European champions are only permitted to field two 'overseas' players under the tournament rules.

Prop Jack McGrath again misses out on selection as Ed Byrne provides cover for Cian Healy, who returns from international duty along with fellow Ireland forwards Tadhg Furlong and James Ryan.

Leinster:J Larmour; A Byrne, G Ringrose, R O'Loughlin, D Kearney; R Byrne, L McGrath; C Healy, S Cronin, T Furlong; S Fardy, J Ryan; R Ruddock (capt), S O'Brien, J Conan.

Replacements:J Tracy, E Byrne, A Porter, M Kearney, D Leavy, J Gibson-Park, N Reid, R Kearney.

Cian Murtagh
BBC Sport NI at Dublin's Aviva Stadium

Image source, Getty

No Johnny Sexton for Leinster today. The Ireland fly-half reported a ‘tightness in his leg’ this week and Leinster have chosen not to risk the playmaker.

The absence of the World Rugby player of the year is obviously a blow for Leinster but it is hardly an unfamiliar problem for head coach Leo Cullen to contend with.

Sexton has played just eight games for his province this season and has not played featured since their provincial derby defeat at Munster at the end of December.

But the champions have a more-than-capable deputy in Ross Byrne, who has played in twice as many Leinster games as Sexton this campaign, including their last two European pool matches against Toulouse and Wasps.

Byrne is also one of the best kick-passers in Ireland and his inclusion today could see plenty of cross-field kicks for Dave Kearney and Adam Byrne to on the wings.

Image source, Gett

Two out of three ain't bad as Meatloaf sang.

But, with Munster and Saracens already into the last four, we have a titanic battle to round off today's Champions Cup quarter-finals.

Leinster v Ulster at the Aviva.