Commanding Jewel is not a certain starter in the final Group One races of the season despite the mare's pleasing exhibition gallop at Moonee Valley.

Connections have given themselves the next 10 days to decide whether to send her to Brisbane for the Group One Tatt's Tiara (1400m) at Eagle Farm on June 21.

Commanding Jewel worked with talented stablemate Word Of Mouth before the first race, the pair quickening over the last 800m.

The duo finished almost on terms with Commanding Jewel clocking 48.42 seconds for her last 800m on slow ground and running home her last 400m in 23.18 seconds.

Jockey Michael Walker said Commanding Jewel, a three-quarter sister to retired star Atlantic Jewel, worked well but tired late in the hit-out.

"She gave me a beautiful feel and did blow-out halfway up the straight," Walker said.

Trainer Leon Corstens said he would assess Commanding Jewel's condition on Sunday morning but would take all of his available time to decide whether to send the mare to Brisbane.

Corstens said he would be happy to scrap Tatt's Tiara plans if Commanding Jewel was not fully fit for the $500,000 contest.

"I've got heaps of time because I don't have to go until Friday week," Corstens said.

"If I was worried at all, I'd just leave her home and go for the spring. I've just got her right and I definitely won't take any chances with her."

Managing part-owner Brad Spicer said Walker was a chance to ride Commanding Jewel in the Tatt's Tiara along with Michael Rodd and Ben Melham.