Last Instalment has been ruled out of the RSA Chase at Cheltenham after suffering a slight injury when winning the Dr PJ Moriarty Chase at Leopardstown on Sunday.
The Philip Fenton-trained seven-year-old, owned by the Gigginstown House Stud, had been a leading fancy for honours at the Festival after taking his unbeaten run over fences to four.
That was his second Grade One success after he took the Fort Leney Novice Chase at Leopardstown in December.
"He's not going to run again this season," said Fenton.
"He was a little sore after Leopardstown, so I thought we'd play safe."