This was supposed to be a weekend of permutations but the sight of Jonathan Sexton walking off with what was confirmed as a calf injury after just 20 or so minutes turned the focus towards his fitness and the likely effects on Ireland’s upcoming Six Nations assault.
The backdrop, really. Castres had nothing to lose and Leinster were already guaranteed a spot in the last eight. The effect on both sides was a much looser game than might have otherwise happened. It cost Leinster who lacked the edge and accuracy of recent weeks.
Take your pick. Leinster were superbly slick and clinical in hitting Montpellier for 57 points at the RDS last week but they spilled balls, slipped off tackles and soaked too many others here and paid the price.
No-one in a Leinster jersey showed anything like the consistency or made the sort of impact to earn this bauble. Steve Mafi was mighty with ball in hand for Castres and captain Rodrigo Capo Ortega got the official nod for his stint in the second row.
Leinster knew this had the potential to be an unstructured ‘jouer, jouer’ game of rugby and so it proved. That suited the hosts more given they had little to lose but the failure to execute basic tasks was equally costly to the three-time European champions on the night.
Greg Garner got it wrong when failing to show Isa Nacewa a yellow card for his block on Julien Caminati early on, one made without a clear attempt to wrap his arms in the attempt. Referees and TMOs shouldn’t really be getting that stuff wrong.
Castres bow out of Europe yet again at the pool stage and turn towards a Top 14 tussle with Montpellier at home this day next week. Leinster, minus a bunch of those who featured last night, travel to Italy where a Guinness PRO12 encounter with Benetton Treviso awaits.