Stewards have grilled leading apprentice Tom Sadler over his Caulfield ride on Lonrockstar, a horse trained by his father.

Lonrockstar was backed from $7.50 into $6 and after settling at the tail of the field finished 11th in the Brett And Mark Wilson Sprint on Saturday.

John Sadler told stewards via telephone he was unhappy with his son's ride, prompting the young jockey to say he was not surprised by his father's reaction.

"I was told to ride for luck or go to the outside but not go busting out," Tom said.

"I was riding to instructions and I've made the wrong decision."

A veterinary inspection showed Lonrockstar had traces of mucus and the horse was also suffering from thumps.

"We will take advice on that before taking the matter further," Bailey said.

"We'll also check some more of the betting."

Sadler snr said he could provide evidence to show betting support for the horse.

The inquiry has been adjourned to a date to be fixed.

Apprentice Michael Dee has been suspended for the second time in consecutive days.

He was suspended for seven meetings on a careless riding charge.

The suspension is to be served once his 15-meeting ban from at Cranbourne on Friday night is completed.

Regan Bayliss, who won the final race aboard Petrology, was fined $600 on a whip breach after being fined $400 for the same offence earlier in the meeting.