Faugheen has had a growth removed from his groin and will not run again before next season.
The rejuventated gelding rolled back the years at Punchestown last week when storming to victory in the Champion Stayers Hurdle.
A trip to France for the French Champion Hurdle had been mooted as a possibility, with Willie Mullins planning a big assault on the valuable prizes on offer at Auteuil later this month.
However, speaking on Wednesday evening, Mullins revealed Faugheen had been sore after the race, and was sent for examination.
“We thought it might have been a muscle problem, but further examination revealed there was a growth,” said Mullins.
“It must have been there for some time and I suppose it possibly explains his in and out form this season.”
Confirming surgery on the 10-year-old had gone well, Mullins said his star would be going on his holidays and would hopefully be back “as good as ever” next season.