A number of Blue Diamond hopefuls will put their credentials on show in the respective Previews at Caulfield.

A field of eight has been declared for Saturday's Listed Preview for colts and geldings while the Group Three Blue Diamond Preview for fillies has already been reduced to a field of 10 with Sydney filly Secret Lady scratched after drawing wide.

Run Naan and fellow stakes winner Long Leaf have opened equal favourites at $3.30 for the male division of the Previews, just ahead of Caulfield debut winner Ollivander at $4.

The Tony McEvoy-trained Oohood, runner-up to Long Leaf in the Merson Cooper Stakes at Sandown on debut in November, has opened the early favourite for the fillies Preview.

She went up at $3 with TAB fixed odds on Wednesday afternoon before drifting to $3.40, with unraced Pure Elation tightening from $3.90 to $3.50.

The Peter and Paul Snowden-trained Pure Elation was a barrier trial winner in Sydney during the spring and won a jump-out at Werribee last week in preparation for her debut.

Three of the horses entered for the male division and two in the fillies Preview, including Oohood, are still among the acceptors for a two-year-old race over 1000m at Moonee Valley on Friday night.

Of those entered for the respective Previews, Pure Elation and Run Naan are the highest in the latest Blue Diamond market on the second line of betting at $13.

The Group One Blue Diamond (1200m) is on February 24.