After a strong performance off the bench last weekend against Connacht in the RaboDirect PRO12, Jimmy Gopperth starts this time at out-half.
In the back row, Rhys Ruddock has failed to recover from the calf injury he suffered in the second half of the Connacht game and, as a result, Kevin McLaughlin comes back in after a recent lay off with a thumb injury to take his place at blindside flanker.
The other change up front sees the in-form Jordi Murphy retained at openside, with Shane Jennings on the bench.
Otherwise there is a familiar feel to the Leinster line-up with Rob Kearney, Dave Kearney and Luke Fitzgerald as the back-three, Fitzgerald having recovered from the illness that ruled him out of last weekend's interprovincial derby at short notice.
Gordon D'Arcy and Brian O'Driscoll are once again selected in the centre, while New Zealander Gopperth will be joined at half-back by Eoin Reddan.
In the pack, it is the same front five as selected last time out in Europe, with Jack McGrath, Sean Cronin and Mike Ross in the front row and Devin Toner and Mike McCarthy packing down behind them.
In the back row Jamie Heaslip will captain the side from number 8, with the aforementioned Murphy and McLaughlin alongside him.
Sunday's game also marks Rob Kearney's 50th Heineken Cup appearance and as a result he will be awarded an ERC Elite Award.
The Louth native will be presented with a specially commissioned ERC cap after the game and joins other Leinster players like Gordon D'Arcy, Leo Cullen, Shane Horgan, Brian O'Driscoll and Malcolm O'Kelly on the list.
D'Arcy is only five appearances short of 100 Heineken Cup caps and would become the first Leinster player to achieve such a feat.
In further good news from the Leinster camp, Fergus McFadden has come through training this week unscathed and will be in contention for a place in the squad for the visit of the Ospreys in round 6 of the Heineken Cup next Friday.
LEINSTER (v Castres Olympique): Rob Kearney; Dave Kearney, Brian O'Driscoll, Gordon D'Arcy, Luke Fitzgerald; Jimmy Gopperth, Eoin Reddan; Jack McGrath, Sean Cronin, Mike Ross, Devin Toner, Mike McCarthy, Kevin McLaughlin, Jordi Murphy, Jamie Heaslip (capt).
Replacements: Aaron Dundon, Jack O'Connell, Martin Moore, Leo Cullen, Shane Jennings, Isaac Boss, Ian Madigan, Zane Kirchner.