Limestone Lad could be off the track until February due to muscle problems in his back.
The James Bowe-trained horse will miss the Woodies DIY Hurdle at Leopardstown next Thursday after a visit to a chiropractor revealed a slight muscle problem.
"It's a slight problem at the back of his saddle area. There has been some muscle wastage which could have affected his jumping over fences," said Bowe's son Michael.
The Boyne Hurdle at Navan in February is a possible return race for Limestone Lad who was due to revert to hurdles next week.
Meanwhile, Hong Kong Jockey Club stewards are to hold an inquiry into statements made by jockey Greg Childs after the running of last Sunday's Hong Kong Mile which he won on Sunline.
Childs was quoted in a Sydney newspaper as having discussed tactics prior to the race with rival jockey Justin Sheehan, who rode third-placed Adam.
Four other Hong Kong-based jockeys will also be interviewed about the race.
The other riders are Douglas Whyte (New Trumps, 4th), Basil Marcus (Charming City, 7th), Weichong Marwing (Billion Win, 6th) and Robbie Fradd (Fairy King Prawn, 2nd).
"The inquiry will centre around the alleged statements made by jockey G Childs," said John Schreck, the Hong Kong Jockey Club Chief Steward.