London Irish - who face a double French test in Pool 1 later this month - will go into those contests without the help of Shaun Edwards.
The Wales assistant coach with responsibility for defence has called an end to his consultancy role with Brian Smith's Exiles in order to concentrate on his international duties.
Edwards has been working with the London Irish squad since the start of the season, one day a week, but will not have any further imput ahead of the tournament matches against Mont de Marsan at Stade Guy Boniface and at home at the Madejski Stadium against Bordeaux-Begles nine days later.
"After consultation with Roger Lewis, CEO of the WRU, I am to concentrate solely on Welsh rugby in the build-up to Rugby World Cup 2015," Edwards said.
"Thus my consultancy work will cease with immediate effect."
Edwards was left out of the British & Irish Lions coaching staff for this summer's tour to Australia and will now concentrate on the Welsh side going into next months' RBS 6 Nations and the summer tour to Japan.
