This is by far the most intriguing match in the RaboDirect Pro12 this weekend as last year's champions host a Cardiff Blues side jam-packed with British and Irish Lions talent.
Cardiff have Lions captain Sam Warburton back in their starting line-up for the first time since last season, whilst Leigh Halfpenny and Alex Cuthbert are in the back-line.
It's going to be a mouth-watering clash between some of Europe's big names, and Brian O'Driscoll is back in the Leinster side as he makes his first start since his shock third Test omission.
Alongside the veteran centre will be his successor as Ireland captain Jamie Heaslip, as well as the likes of front row Cian Healy and full-back Rob Kearney.
The clash between the Ireland and Wales heavyweights at the RDS takes on greater significant as Matt O'Connor's men suffered a surprise loss to Glasgow Warriors last weekend.
Cadriff are also smarting from a defeat, too, following a shock 30-25 defeat by Zebra last weekend, and the visitors could move ahead of fifth-placed Leinster with victory.
For the defending champions, it will be a chance to amend the problems which have arose at the start of the campaign, as well as giving key players some much-needed match practice.
Of particular interest will be Ian Madigan's performance at number 10 for Leinster after suggestions that Jimmy Gopperth could be played in Jonny Sexton's role.
Leinster: Rob Kearney; Fergus McFadden, Brian O'Driscoll, Noel Reid, Dave Kearney; Ian Madigan, Isaac Boss; Cian Healy, Sean Cronin, Martin Moore; Devin Toner, Quinn Roux; Rhys Ruddock, Dominic Ryan, Jamie Heaslip (capt).
Ca rdiff Blues: Leigh Halfpenny; Alex Cuthbert, Owen Williams, Dafydd Hewitt, Harry Robinson; Rhys Patchell, Lloyd Williams; Sam Hobbs, Matthew Rees (capt), Taufa'ao Filise, Lou Reed, Filo Paulo, Josh Navidi, Sam Warburton, Andries Pretorius.