Parish Hall, last season's Dewhurst winner, will miss Saturday's Irish 2,000 Guineas and the Derby at Epsom next month because of a leg infection.
The Jim Bolger-trained colt was favourite for the Curragh Classic after winning the Group One Dewhurst at Newmarket last October.
"It's not a very pleasant experience so close to the race," Bolger said.
"At this stage I've no idea how long it will keep him off for but this rules out Epsom as well."
Parish Hall is a son of Bolger's champion juvenile Teofilo.
He is owned by Bolger's wife, Jackie.