Sizing John, winner of the 2017 Cheltenham Gold Cup, has suffered a setback and will not race this season.
The frustrating news was broken by trained Jessica Harrington, who was unable to defend his crown last season due to injury.
She reported on her Unibet blog: “Unfortunately, Sizing John has met with a setback and he will miss the remainder of this season. After routine exercise yesterday, I wasn’t happy with him and our vet came down and examined him.
“He has confirmed to me that he has met with a setback, which means that he won’t run at Cheltenham or Punchestown. His owners have been informed and, naturally, they are very disappointed, as is everyone at Commonstown.
“We will do what is best for him and we’ll speak to our veterinary team over the coming weeks and months and we will keep everyone posted on his progress.”