Races over a mile distance usually test the stamina of young horses but trainer David Hayes has no such concerns with Derby hopeful Eagle Island.

In fact, Hayes would prefer it if The Golden Fleece & Court Jester Plate at Caulfield on Saturday was even further than 1600m.

"He's a very strong young stayer and my only worry tomorrow would be whether the mile is going to be too short," Hayes said.

Two-year-old Eagle Island has already proven himself at 1600m with a debut win in Listed grade in Adelaide and Hayes says the well-bred colt has improved since.

The son of Fastnet Rock's runs will be spaced but Hayes is looking to keep the colt going to the Victoria Derby (2500m) in November.

The trainer, with the benefit of his Euroa training property, has already proven he can keep his horses racing well for long preparations with the best advertisement being iron horse Whisper Downs who has won seven races in a campaign which started last August.

Hayes said Eagle Island would not run again after Saturday until a Listed race in July over 1600m.

"He will have one of those long extended Whisper Downs-style of preparations," the trainer said.

A $2.30 favourite to remain unbeaten, Eagle Island is just shading last start Caulfield winner Polanski ($2.80) who trainer Robbie Laing also has Derby aspirations.

Eagle Island is considered Hayes' best chance from his seven Caulfield entries but Readings is also expected to run a bold on-pace race in the Cattanach's Jewellers Handicap (2380m) with on-loan 3kg apprentice Kayla Nisbet chasing a breakthrough city win.

"She's got no weight and is very fit," Hayes said of Readings.

"If by chance it rains she'll be really hard to beat, but if not she'll still be a good chance."

Stakes winner Gybe will need the track to remain in its dead range to take her place in the Responsible Gambling Awareness Week Handicap (1200m).

Formerly trained by Anthony Cummings, Gybe made her debut for Hayes with a sixth in the Wangoom Handicap at Warrnambool.

"She's been very frustrating - she stops rain," Hayes said.

"She's a wet tracker. If the track is dead (or worse) she'll run and if she runs she'll be competitive."