Brilliant debut winner Earthquake is among 25 youngsters left in contention to give Peter Snowden a Blue Diamond Stakes win before he steps down as Darley Australia's head trainer.

Darley announced on Wednesday Snowden will be quitting his post later in the Australian racing season.

Snowden will step down at the end of the Sydney autumn carnival but has promised to keep his focus on delivering results for the Darley team.

And with a seemingly unlimited pool of two-year-old talent to work with, winning another Blue Diamond Stakes in 2014 will be high on Snowden's farewell agenda.

Snowden won the Blue Diamond in 2011 with star colt Sepoy who went on to claim the Golden Slipper.

Sepoy played a big part in the Darley operation's clean sweep of that year's five Australian Group Ones for two-year-olds.

There are 505 two-year-olds still in the running for the Blue Diamond (1200m) which will be run at Caulfield on February 22.

Earthquake made a big impression with a debut victory at Randwick recently, while stablemate Memorial who won at Rosehill last Saturday is also one of Darley's babies still in contention.

Gai Waterhouse has the most horses left in the Blue Diamond first declarations with 42, one more than David Hayes.

Peter Moody and Mick Price both have 29.