The Jessica Harrington-trained Jezki, favourite with many firms for next year's Ladbrokes World Hurdle at Cheltenham, has been ruled out for the upcoming season with a leg injury.
A Champion Hurdle winner in 2014, the seven-year-old had been back in training at Harrington's Kildare base since last month, and she admitted: "It's hard to stomach, but it's one of those things."
The trainer revealed: "Unfortunately he's out for the season. He came back into training in the second week of August and we found he had some heat in his leg yesterday (Thursday) morning.
"He will need plenty of time to recover we've decided that he won't be running this season."
Jezki would have been most likely to start his campaign in the Hatton's Grace Hurdle at Fairyhouse, which he won in 2013. He finished last season on a high by winning Grade Ones at both the Aintree Grand National meeting and the Punchestown Festival.
Having finished fourth behind Faugheen in the Champion Hurdle, the JP McManus-owned son of Milan won the 2m4f Doom Bar Aintree Hurdle and then got his revenge on Hurricane Fly in the 3m Ladbrokes World Series Hurdle at Punchestown in April.
Meanwhile, trainer Mick Halford is looking forward to the Cambridgeshire at Newmarket this afternoon where he'll attempt to land another big pot with the Godolphin-owned three-year-old Portage.
Second in the Irish equivalent last month, Portage will be one of the leading fancies for today's major handicap.
"The ground was probably a little against him the last day in the Irish Cambridgeshire," admitted Halford.
"He's been in good form since and the better the ground, the more he'll like it.
"The step up to nine furlongs should suit him. He was a bit unlucky at Royal Ascot, but came good there in July, though the ground was soft.
"He's in good form and ready to go," Halford added.
"He'll be my first runner in the Cambridgeshire."