The performance of Listed winner Thurlow in the Chairman's Stakes at Sandown will decide if she is given her chance in the Blue Diamond Stakes.

But trainer Robert Smerdon insists Thurlow's unbeaten stablemate Fontiton - the Blue Diamond favourite - is a better juvenile and his assessment means Thurlow could take a different path.

Thurlow, raced by Qatar Bloodstock, will gallop at Sandown on Wednesday before resuming in Saturday's Group Three race for juveniles at the same track.

The daughter of Sebring finished second to Antelucan at her debut last spring at Flemington before winning the Merson Cooper Stakes at Sandown.

"She trialled OK last week at Cranbourne and Saturday's run will tell us where we sit," Smerdon said.

"Whether she's good enough (for the Blue Diamond), I don't know.

"Things can change, circumstances like track conditions and barriers, but Fontiton has always been the superior of the two.

"So based on that she might be better going for an easier target."

He said the Group Three TBV Thoroughbred Breeders Stakes (1200m) for two-year-old fillies next month at Flemington could be a suitable option.

The Chairman's Stakes nominations include Maribyrnong Plate winner Prompt Return, Godolphin's city-winning colt Bantam and the David Hayes and Tom Dabernig-trained Haybah who finished second to Fontiton last start.

Smerdon elected not to give Thurlow a jumpout on Tuesday but took the chance to give Fontiton a look at the Caulfield course proper ahead of the Blue Diamond fillies Prelude on Saturday week.

Fontiton resumed with a narrow win in the fillies Blue Diamond Preview last week and sat off the speed in Tuesday's hit-out before running home well for a close second to the Mick Price-trained Stylish Assassin.

"She wasn't there for a hard hit-out but it was a really good opportunity to give her a look at where she'll be racing at her next start," Smerdon said.

"I'm pretty happy where she's at."

The Price-trained Blue Diamond second favourite Secret Agenda won her jump-out to tune up for her clash with Fontiton in the Prelude.

"We haven't got a lot of Blue Diamond horses left (in contention), but she is a good one," Price said.