The seven-year-old won the Fortria Chase at Navan on his reappearance last month, beating subsequent Tingle Creek fourth Central House by three-quarters of a length.
Nickname won two of his five starts last term and although Brassil knows his charge is facing a tricky task against the Gold Cup hero, he is hoping the likely testing ground will play to his strengths.
“The horse is in great form at the moment,” said Brassil.
“Conditions and trip seem to be in his favour so he will take his chance, even though this will be the biggest test he has encountered so far over fences.”
War Of Attrition is still an intended runner in the Grade One feature, despite trainer Mouse Morris’s concerns over the ground.
He said: “War of Attrition has won five times at Punchestown and likes the place.
“The heavy ground is an obvious concern, but the horse is very well in himself and the intention is to run on Sunday.”
The going at Punchestown is currently heavy and track manager Dick O’Sullivan is not expecting much improvement before the weekend.
He said: “The forecast is unsettled and the ground will be testing on Sunday.”