Karen Kersley delayed back surgery to ensure Starlight Lady starts in tomorrow's Perth Cup.
Kersley rides the mare at trackwork but after having the operation won't be able to work for some time.
Starlight Lady, to be ridden by Shaun Meeres in the cup, has flown under the radar to be $31 on Player.
The Fantastic Light mare will carry the famous yellow and black maltese-cross colours of owners Neville and Sue Duncan's Oakland Park Stud in the $500,000 feature.
"I am now due to go into hospital next week and won't be able to work for several weeks," Kersley said.
Starlight Lady goes into the Perth Cup with a top record of three wins and three placings at her past seven starts.
The six-year-old's sole blemish was when bottled up on the rail on straightening in the ATA Handicap (2200m) on December 19, but she made up ground to finish four lengths behind Bridgestone.
"The Perth Cup came up when she won at the opening meeting of Ascot (October 20)," Kersley said.
"Neville was talking about going to the paddock and bringing her back for the Bunbury and Pinjarra cups.
"I didn't want to spell her because she was doing so well. She was actually putting on weight.
"So I said if you want to try something silly let's go for the Perth Cup.
"So often you will send a horse to the paddock and it does not come back the same horse."
Kersley said spacing Starlight Lady's runs was the key to the mare racing so well.
"She pulls up well and I am just looking after her," she said.
"Every day she looks at me and she wants to go out and work.
"This time in she is just loving being in the stable she is a happy, happy horse.
"She always has had ability but she would have about four runs and that was it.
"This time she just keeps eating and doing so well."