Thousand Guineas winner Commanding Jewel has joined her unbeaten half-sister Atlantic Jewel as an autumn carnival absentee.
On the verge of starting the serious part of a preparation aimed at having her peak for the Sydney carnival, Commanding Jewel has suffered a joint injury.
"She has tweaked a joint and will need a little bit of an operation," the filly's managing co-owner Brad Spicer said.
"It's nothing serious but it's a shame because we deliberately gave her a light spring to concentrate on the autumn."
By leading sire Commands, Commanding Jewel cemented her standing as one of Australia's most valuable fillies when she completed her first racing campaign with a Group One Thousand Guineas win in October.
Spicer said trainer Leon Corstens had in the past week started to increase Commanding Jewel's workload.
"She was about four weeks into her preparation and Leon was just about to up the ante with her," he said.
"Thankfully the injury isn't long-term and she will be back for the spring."
Atlantic Jewel, the 2011 Thousand Guineas winner, has been off the scene with a troublesome tendon injury since last year's Sydney autumn carnival.
Unbeaten in seven starts, Atlantic Jewel has been cleared to return to work but trainer Mark Kavanagh will reportedly take a conservative approach with the mare and save her for the spring.
In spite of Commanding Jewel's setback, there are high hopes for the autumn and winter carnival prospects of horses racing under the Spicer Thoroughbreds banner.
"Even without Commanding Jewel we've probably got the best depth we've ever had," Spicer said.
The team will include South Australian Derby winner Zabeelionaire, import Rosello, three-year-olds Sekiguchi and Wolfpack as well as Fantome Gris, a two-year-old who is in the running for a Sydney autumn campaign.