"That way we'll get to see how she handles the 2000m in the Caulfield Stakes, rather than finding out for the first time in a Cox Plate," Corstens said.
"If she didn't get the 2000, or wasn't happy in that, we could rethink and go back to the Myer Classic."
Commanding Jewel won at Moonee Valley in her second start in August 2012, while her only other start at the track was a sixth in the Carlyon Stakes over 1000m in August last year in her first start for 44 weeks.
The 5-year-old daughter of Commands sat three wide in the Let's Elope Stakes last start but showed her class in beating a good field of mares.
The Stocks Stakes nominations include Dear Demi, Launceston and Hobart Cup winner Epingle, Solicit and Text'n Hurley.
Damien Oliver retains the ride on Commanding Jewel and he will also partner stablemate Awesome Rock in Sunday's Caulfield Guineas Prelude (1400m) at Caulfield.
Awesome Rock finished third first-up in the McNeil Stakes before his fourth in the Danehill Stakes at Flemington.
"He's a lot fitter than he was second-up," Corstens said.
"He probably needed those first two runs and he'll go into the Guineas Prelude spot on."