Castres Olympique v Leinster
Pierre Antoine, Sunday (KO 1.0 SS3)
The importance of Luke Fitzgerald to Leinster can be gauged by the fact that coach Matt O'Connor has thrown him straight in at the deepest end of this Pool.
It is a miraculous recovery, a sign of the dedication Fitzgerald still practices as he comes back for the umpteenth time from injury.
O'Connor repositions Ian Madigan at twelve, the excellent Zane Kirchner at full-back, Darragh Fanning on the right wing and Fitzgerald on the left in a reshuffled back division.
Isaac Boss at scrum-half and Kane Douglas in the second row complete the three changes.
Neither Mike Ross (groin) or Rob Kearney (back) have been able to overcome injury and Noel Reid slips to the bench.
The 2013 French champions removed all negative thoughts from their pale imitation of recent years in the Top-14 League, where they currently languish in 12th, to put Harlequins to the pin of their collars at The Stoop.
Leinster know all about Castres' home pridefrom the shell-shock of going 14-0 down while the scrum was being pulverised there last January.
However, superior conditioning allowed them to battle back for a 29-22 victory to end Castres 18-match unbeaten run at home.
Leinster: Z Kirchner; D Fanning, G D'Arcy, I Madigan, L Fitzgerald; J Gopperth, I Boss; J McGrath, S Cronin, M Bent, D Toner, K Douglas, R Ruddock, D Ryan, J Heaslip (capt).