Caulfield trainer Ciaron Maher has undergone surgery for a broken femur after champion mare Jameka threw him at trackwork at Caulfield on Friday.
Maher was taken by ambulance to the Alfred Hospital and was operated on following the incident at about 4am. Jameka was not injured and remains on the comeback trail.
Maher was aboard Jameka trotting in the exercise area when she whipped around and threw him heavily to the ground.
The unfortunate break has ended Maher's quest to ride in next month's epic Mongol Derby in China but it is believed fellow trainer Adrian Corboy could take his place.
It is also expected that the Mongol Derby Gala Ball, to be held at Caulfield on July 21, will proceed. The ball is set to raise funds for the Peter McCallum Cancer Centre.