Outstanding mare Appearance will be retired after suffering a leg injury.
The four-time Group One winner was unbeaten in three starts this campaign and was the favourite for next month’s Doncaster Mile.
“It is an unusual injury,” trainer Guy Walter said.
“She has a bit of a tear to a ligament in the back of a joint in her off foreleg.
“She has been a wonderful mare and she will be retired now.”
Appearance, who is owned by Sheikh Mohammed’s Darley Australia, has had a history of muscle problems which have been carefully managed by Walter who trained her to nine wins from 19 starts.
Her most recent victory was in the Group One Canterbury Stakes earlier this month.
Walter will now rely on Streama and Toydini in Saturday’s George Ryder Stakes at Rosehill.
Kerrin McEvoy will ride triple Group One winner Streama while Blake Shinn will be aboard Toydini.