Godolphin's leading Golden Slipper contender Astern will miss a vital lead-up race because of an elevated white cell count.

His withdrawal from Saturday's Todman Stakes leaves a possible field of five headed by Capitalist who has been replaced as the Slipper favourite by Blue Diamond Stakes winner Extreme Choice.

Trainer John O'Shea said Astern had not missed any work and his temperature on Friday was normal.

He is expected to run in a barrier trial at Warwick Farm on Thursday.

Astern is an $11 chance for the $3.5 million Golden Slipper on March 19 with Extreme Choice at $3.50 from Capitalist at $3.80.

The Peter and Paul Snowden-trained Capitalist is unbeaten in three starts and is at $1.50 to win the Todman.

Honesty Prevails is the $1.95 favourite to win the two-year-old fillies race on Saturday, the Reisling Stakes, for Warwick Farm trainer Rick Worthington.

Calliope, a $26 Slipper chance for Godolphin is at $2.80 for the Reisling.

The winners of Saturday's juvenile features gain automatic entry to the Slipper field.

Although Capitalist has earned more than $1.4 million, only 90,00 counts towards the Slipper with the remainder earned in Magic Millions sales-restricted races.