Officials have defended their rating of the Flemington track on Boxing Day in light of criticism from trainer Mick Kent over a career-ending injury to imported stayer Unusual Suspect.

The nine-year-old, who has competed in two Melbourne Cups and won last month's Werribee Cup, suffered a fractured pastern in the Bagot Handicap in which he finished second last.

Kent said stewards should have upgraded the track from a Good 3 to a Good 2, allowing trainers the option of scratching their runners.

He said he had walked the track and described it as as firm as he had seen it and Racing Victoria trackwalkers should have also reported its condition properly.

Kent told steward Robert Cram of his concerns but said the track was upgraded only once, from a Dead 4 to a Good 3 after the first race.

Cram said RV had had "mixed" feedback from jockeys after the Boxing Day meeting but Kent was the only trainer who had complained to him.

"One leading jockey said he wished the track was like it every race meeting," Cram said.

"The track did have an excellent cover of grass on it which did give it that little bit of cushion.

"The grass was actually the thickest and longest I've actually seen it at Flemington for some time.

Kent said the track was quick from the opening race.

"It was fast ground," Kent told Melbourne's Racing Sports Network radio.

"I walked it and, especially the last 600, I thought it's easily a Good 2...very firm, no give.

"It was the firmest I've walked it, I think.

"It just would have been good to know that. I shouldn't have run the horse."

In October, trainer Terry O'Sullivan scratched favourite Exceptionally from the Bart Cummings believing the Flemington surface was harder than the Good 3 official rating.

Stewards allowed the withdrawal of the mare after the trainer told them she could not possibly win.