Hong Kong-based Australian jockey Nash Rawiller will miss the Doncaster/Derby meeting at Randwick because of travel difficulties.
Among his scheduled rides on Saturday were the Chris Waller-trained The Lord Mayor in the Australian Derby and Tchaikovsky from the Peter and Paul Snowden stable in the ATC Sires' Produce Stakes.
Waller's racing manager Charlie Duckworth said Rawiller was unable to arrange a flight back to Hong Kong in time for Sunday's meeting at Sha Tin.
Corey Brown will now ride The Lord Mayor who finished fourth in the New Zealand Derby before being transferred to Waller.