For Shawn Mathrick, making the switch from rodeos to training a Victoria Derby runner isn't that much of a leap.

The Cranbourne trainer affectionately recalls his rodeo days, albeit 30 kilos and several injuries ago.

"I got smashed up. I had seven or eight operations on my pelvis and got my pelvis fused, broke my back, but I loved rodeo. It took me all over the world and I met great people.

"I love horses so training, it sort of goes hand in hand."

Mathrick gushes about Ayers Rock, the three-year-old who on Saturday becomes his first contender for the $1.5 million Victoria Derby.

"I'm more about the horse. I mean the money's great but really I've got a lot of admiration for this horse so it would just say to everyone what I've been saying - that this is a good horse.

"Look, if he doesn't win the Derby I'll still think he's a great horse."

Mathrick paid $110,000 for Ayers Rock after selecting the yearling for his athleticism.

"I just thought he was a great-looking athlete. He had a great shoulder and good hindquarters and short across the back so I thought he was a nice horse."

Mathrick said he knew when he broke in Ayers Rock that he was on to something special.

"Even from the first time we rode him he had a fantastic gait and I said if this horse can sprint, he's the type of horse who could win the Derby."

Mathrick has eight horses in work at the moment at his Cranbourne stable.

"We own most of our horses ourselves so if we don't win, we don't eat, but you can see I've been eating," he said with a laugh.

Wife Kim owns 40 per cent of Ayers Rock - "so she's in charge, I do as I'm told" - who has so far won $130,000 in prize money.

Mathrick says he has big wraps on the colt as he attempts to take home the $900,000 first prize on Saturday.

Asked what a Derby win would mean to him, Mathrick quickly quipped "450 large".

"It would be fantastic," he added.

"We want to win but you want to see the horse win it too."