Damien Oliver is in danger of missing the ride on Wandjina in the Australian Guineas after being suspended for 12 meetings at Ballarat on Thursday.
Oliver was outed on a careless riding charge after causing interference near the 500m when winning on the odds-on favourite Cornrow.
The suspension begins after Saturday's Blue Diamond Stakes meeting at Caulfield and he will be free to ride again at Ballarat on March 12, returning in time for the Australian Cup and Newmarket Handicap meeting at Flemington.
Oliver has indicated he will appeal the suspension.
The jockey won the CS Hayes Stakes on the Gai Waterhouse-trained Wandjina at Flemington last Saturday.