A distance test for two-year-olds on the penultimate weekend of the season is something trainer David Hayes believes Huntly Castle will appreciate at Flemington.

Saturday's Byerley Handicap is over 1800m and is a chance for middle distance and staying prospects to be tested over further than 1600m against their own age group for the first time in Melbourne during the season.

Huntly Castle heads into the race off a win in a 1600m maiden against older horses at Bendigo at his third start recently and Hayes believes the colt has continued to progress since.

"Back against his own age I just don't think the 1800 metres will bother him at all," Hayes said.

"I think he has probably improved (since last start) which is quite good.

"I think he is going to make a nice middle-distance horse and this will be the first time probably at his preferred distance.

"If he wins this we might back off him and bring him back in the spring."

The winner of the Byerley will be assured of a place in the Victoria Derby and or VRC Oaks in November should they head that way.

Hayes, who trains in partnership with his son Ben and nephew Tom Dabernig, said the Derby Trial (1800m) on September 25 could be an option for the colt to progress to after Saturday.

Huntly Castle was the equal $4 favourite in an early market on Wednesday along with the Gai Waterhouse and Adrian Bott-trained colt Echo Lad who won over 1600m at Warwick Farm last week.

The Tony McEvoy-trained filly Marndarra, who won over 1550m in a maiden in Adelaide at her second start, was at $4.80 in the field of 13.