Traditional caution gave way to quiet enthusiasm after trainer Leon Corstens watched his star filly Commanding Jewel prepare for her return to racing at Moonee Valley on Saturday.

"She had a nice hit-out ... she's pulled up well," Corstens said following the mare's gallop at Moonee Valley.

"I don't know if she's quite quick enough over 1000 metres, but as long as she's getting home I'll be happy."

But when pressed on how competitive he thought Commanding Jewel would be on Saturday, Corstens gave only one word in reply: "Very."

Commanding Jewel, the three-quarter sister to the unbeaten Atlantic Jewel, is likely to be opposed by some high-speed opponents in the Carlyon Stakes, including the straight-track specialist Adamantium, Elite Elle, Adebisi and General Truce.

But both Corstens and Commanding Jewel's new rider Craig Williams believe the abundance of speed will suit the mare whose best win came at her most recent start in the Group One Thousand Guineas (1600m) last October.

"I'd be surprised if it was too short for her," Williams said.

"I think she's quite brilliant, and she'll have some very fast horses up ahead of her to make sure there's a good pace."

Williams, who is keeping the saddle warm for the suspended Damien Oliver, rode Commanding Jewel for the first time on Tuesday.

With instruction to give her a solid gallop, Williams increased the pressure, finishing off the work in 23.9 seconds on the extreme outside of the track.

"When I asked her to improve she was very sharp to respond," Williams said.

"She was in front out very wide and when I asked her to be solid in the straight she balanced up and quickened again.

"She's quality."

Commanding Jewel has the Group Two Let's Elope Stakes (1400m) at Flemington on September 7 pencilled in for her next run with her ultimate spring goal the Group One Cox Plate (2040m) at Moonee Valley on October 26 as her ultimate spring target.