Justin Burnell admits the Cardiff Blues are massive underdogs in their quarter-final clash with reigning Heineken Cup champions Leinster in Dublin.
Cardiff's Pro12 play-off bid has been dented after losing their last three games and the Blues make seven changes as Martyn Williams returns from injury.
Blues are without Paul Tito, Deiniol Jones, Jamie Roberts and Sam Warburton.
Leinster make four changes as forwards Richardt Strauss, Cian Healy, Sean O'Brien and captain Leo Cullen come in.
The backline is unchanged with Eoin Reddan partnering Jonathan Sexton, who has amassed 300 points in 27 European appearances, at half back.
South African loose-head prop Heinke van der Merwe is named alongside five Ireland internationals on the bench including Sean Cronin, Shane Jennings and Fergus McFadden.
Veteran openside Williams, blindside Michael Paterson and captain Rush make up a new-look Blues back row while Gethin Jenkins and Marc Breeze come in alongside Scott Andrews in the front row.
Hooker Breeze replaces injured Ryan Tyrell (ankle) while Wales loosehead comes in for prop John Yapp while in the backs Dan Parks is in for Ceri Sweeney at fly-half and Dafydd Hewitt replaces injured Wales centre Roberts, who is expected to be out for six months due to a knee injury .
The Blues only hope of silverware is now in Europe after a disappointing run of four defeats in five games and their week did not improve as Gavin Henson was sacked after misbehaving on their return flight from Glasgow Warriors last weekend.
Wales captain Warburton (shoulder), lock Jones (shoulder), Tito (head), T Rhys Thomas (neck) and Fau Filise (shoulder) are out but the Welsh side will face a Leinster side who are unbeaten in this season's Heineken Cup and lead the Pro12 league.
Burnell is aware everybody has written off the Blues' chances of victory over a Leinster side which has lifted the Heineken twice in the last three years.
"Rightly so, everybody will write us off, which in all fairness, is quite nice for us because there will be no pressure," said Blues coach Burnell.
"If we go there, give it our all and if we come away with a good performance and a good result it will be totally unexpected.
"Nobody is going to expect us to go there and win, so good luck to Leinster."
Burnell, along with his fellow co-coach Gareth Baber, have led the Blues to a first quarter-final in European rugby's premier tournament since 2009.
Leinster: R Kearney; I Nacewa, B O'Driscoll, G D'Arcy, L Fitzgerald; J Sexton, E Reddan; C Healy, R Strauss, M Ross, L Cullen (capt), B Thorn, K McLaughlin, S O'Brien, J Heaslip.
Replacements: S Cronin, H van der Merwe, N White, D Toner, S Jennings, I Boss, I Madigan, F McFadden.
Cardiff Blues: Leigh Halfpenny; Alex Cuthbert; Casey Laulala, Dafydd Hewitt; Tom James; Dan Parks, Lloyd Williams; Gethin Jenkins, Marc Breeze, Scott Andrews, Bradley Davies, James Down, Michael Paterson, Martyn Williams, Xavier Rush (c)
Replacements: Kristian Dacey, John Yapp, Sam Hobbs, Macauley Cook, Maama Molitika, Richie Rees, Ceri Sweeney, Gavin Evans.
Referee: Dave Pearson (RFU)
