Rosehill Racecourse is on stand-by to host the rich Inglis Millennium meeting if Warwick Farm becomes waterlogged.

Racing NSW says it has been monitoring the forecast for western Sydney and will continue to do so in the lead-up to Saturday.

The Bureau of Meteorology is predicting the following rainfall for Warwick Farm: Thursday - 6 to 10mm, Friday - 20 to 30mm and Saturday - 30 to 45mm.

"In consultation with the Australian Turf Club, as a contingency, the Rosehill Gardens racecourse has been placed on stand-by to conduct the meeting should the Warwick Farm track be deemed unsafe to race on," Racing NSW stewards said.

Stewards will also keep a close watch on the condition of the Rosehill surface.

The meeting includes the $2 million Inglis Millennium for two-year-olds and the $1 million Inglis Sprint.