Melbourne Cup-winning jockey Michelle Payne has been fined $1000 for a social media post directed at racehorse owner Brae Sokolski.

Payne reacted to the decision on Tuesday to replace jockey Linda Meech with Mark Zahra aboard Victoria Derby contender Thought Of That by posting a tweet Racing Victoria stewards said was offensive to the colt's managing owner.

"The stewards found Ms Payne's comments to be offensive towards Mr Sokolski when she stated 'not for the public to decide but the public can recognise you as a pig'," Racing Victoria stewards said.

"After considering Ms Payne's guilty plea and her prior offences, stewards have issued her a fine of $1000."

Payne deleted the post on Tuesday.

Meech has ridden the Ciaron Maher and David Eustace-trained Thought Of That in his past three starts including an eight-length maiden win at Donald two starts ago and a 3-3/4-length win in the Group Three Caulfield Classic last Saturday week.

Sokolski told RSN927 on Wednesday morning he found Payne's comments upsetting.

"Firstly, you're entitled to an opinion on an owner's decision regarding a jockey engagement, I've got no issue with that," Sokolski said.

"You are not entitled to challenge the right of an owner to make that decision.

"You're most certainly not entitled to accuse or even imply insidious motives for that decision, without any evidence whatsoever, and you're sure as hell not entitled to defame and personally abuse an owner for a decision."

Sokolski said "not even a skerrick of the decision" had anything to do with gender.

"The decision was made purely on the merits of the race and what we thought was in the best interests of the horse and the ownership group," he said.

"You can accuse me of lacking sentiment, and I'll take that on the chin, but that's about it."

Sokolski said the decision to replace Meech with Zahra had been made on Monday and the trainers were informed accordingly.

Meech galloped the horse in trackwork at Caulfield on Tuesday unaware she had been replaced.

Thought Of That was the $3.90 second favourite for the Derby on Wednesday.

Sokolski said the irony was the colt still may not run in the Derby, with connections to weigh up whether to wait another week for the weight-for-age Group One Mackinnon Stakes.

He said there were good cases for running in either race.