With Melbourne jockeys unable to travel to Sydney to compete until further notice, the Anthony Freedman stable has locked in its riders for the opening day of The Championships.

On Tuesday, Racing NSW announced the jockey pool in the state would be segregated into three regions - metropolitan, north, and south/west.

Any jockey who was not already in the state by Monday afternoon can no longer ride in NSW until further notice under the new coronavirus biosecurity measures.

This rules out a number of high profile Melbourne jockeys including Santa Ana Lane and Super Seth's regular rider Mark Zahra.

A pool of 25 jockeys is allowed to ride in the Sydney metropolitan area including visiting English jockey Tom Marquand who has been booked for the Freedman-trained Caulfield Guineas winner Super Seth in Saturday week's $3 million Doncaster Mile at Randwick.

Nash Rawiller has been booked for stablemate Homesman in the Doncaster.

Tim Clark will ride defending champion Santa Ana Lane in the Group One TJ Smith Stakes while Tommy Berry replaces Damien Oliver on Victoria Derby winner Warning in the Group One Australian Derby.