The popular Happy Clapper has a virus and will miss The Gong robbing the $1 million race of its star attraction.
Trainer Pat Webster said the gelding developed a temperature over the past few days and had a slight virus.
He had been scheduled to trial on Tuesday ahead of The Gong at Kembla Grange on Saturday week but missed the hit-out.
"It's a shame. He had a tendon problem as a young horse but throughout his career he's never had anything like a virus," Webster said.
"He has always been so healthy so it's a first.
"We have treated him and we have just run out of time to get him ready.
"He owes us nothing and it just means he will have an extra week or so in the spelling paddock.
"We can give him a rest and get him back for the autumn and The Championships."
The Triple Group One winner's most recent start was his victory in the Craven Stakes at Randwick.
That win was his first at 2000 metres but many of his previous attempts have been in races won by Winx.
Webster said now Happy Clapper had proved himself at the distance he and owner Michael Thomas would look at running him in 2000m-races in his next campaign.