The prospect of a firm track doesn't fill trainer Mick Kent with much encouragement ahead of the Mornington Cup.

Kent has Oncidium Ruler engaged in the Listed race over 2400m with the winner earning a ballot exemption for this year's Caulfield Cup in October.

Oncidium Ruler, a placegetter in the Ballarat Cup in November and the Pakenham Cup in December, has had three runs since those performances.

He finished fifth at Moonee Valley before a let-up and since has run third behind Angelology and Velox in the Wangaratta Cup on March 4 before a fourth behind Berisha in the Yarra Valley Cup last Sunday.

Kent said the gelding had felt the ground at his past two starts with the tracks rated good 4 surfaces.

The Mornington surface on Saturday is also rated a good 4 and received 36mm of irrigation in the seven days before acceptances on Wednesday with a further 2mm of rain.

Veteran trainers at Mornington said strong winds on Wednesday would have had a drying effect on the track.

There are showers forecast for Saturday which Kent said would need to eventuate for the gelding to take his place.

Oncidium Ruler is an out-and-out stayer having won over 2400m at his second race start and is a winner over 2500m at Moonee Valley.

"We've left him in the race as there's a chance it will be raining on Saturday," Kent said.

"That would have to come for us to be running him.

"He's been feeling the ground at his last couple and I would imagine it would be pretty firm if there isn't any rain."

Oncidium Ruler has been specked ahead of Saturday's race firming from $26 to $18 and will be ridden by in-form apprentice Stephanie Thornton who is indentured to Kent.

The market is dominated by the Darren Weir-trained import Kings Will Dream who has been backed from $3.40 to $2.70 since the final field was announced.

Kings Will Dream is unbeaten in four Australian starts and is coming off successive wins at Flemington over 1600m and 1800m and will be ridden by Dean Yendall who was aboard in his win over 1200m at Warrnambool in January.