An injury to close mate Chad Lever has enabled Rory Hutchings to combine with unbeaten Bon Amis at Rosehill.

Chad Lever's serious tumble at Scone has presented an opportunity for Rory Hutchings, a jockey familiar with pitfalls since moving from New Zealand.

Hutching was three times champion apprentice at home and also took the junior title in Sydney in 2015/16.

But the 22-year-old has struggled with weight and suspension at regular intervals while in Sydney.

Hutchings has been suffering this week so he can maintain his association with the unbeaten Jason Deamer-trained Bon Amis at Rosehill on Saturday.

He was keeping an eagle eye on the scales at Canterbury on Wednesday in order to weigh out at 56.5kg for Saturday's Benchmark 80 Handicap (1100m).

Hutchings first rode the Jason Deamer-trained four-year-old at Newcastle last month by accident, rather than design.

"My good mate Chad got hurt. He rides most of Jason's, so I was in the right place at the right time," Hutchings said.

Lever, who is still recovering from from injuries sustained in the fall in August, gave Hutchings an idea of what to expect from Bon Amis, the favourite to win five in a row.

"Chad let me know he was still quite new and green. It didn't really matter fresh up, he was just too good," Hutchings said.

"He's still putting things together. He's winning on raw ability at the moment. I think he's going to be a better chaser with a horse in front to run down."

Hutchings is also making up for lost time after a slow and frustrating start to riding in an ultra-competitive environment.

He recorded a metropolitan double at Rosehill with Bon Amis and the Bjorn Baker-trained Redouble on November 11, his first brace in the city since October last year.

Hutchings has 11 winners overall this season, compared to 24 for 2016/17.

"It's all starting to come together. I've sort of got in with Thoroughbred Leasing. I've done a little bit of travelling for them and got into form," Hutchings said.

Ex-pat New Zealander Bjorn Baker has also been supportive by adding an occasional city ride to Hutchings' country commitments.

Controlling his weight continues to be an issue but Hutchings is determined to persevere.

"It's always going to be a struggle but I've learnt more about my body and how to keep weight down." Hutchings said.

A trip home to Matamata at the start of the year also gave Hutchings food for thought.

"My weight was 60-odd (kg) and I didn't really have the hunger for the game," Hutchings said.

"I rode a couple of heavyweights and thought 'What am I doing back here? Sydney's the place for me'."