There are a few empty boxes at Don Robb's Wyong stable and he's hoping Big Bonanza can help fill them.

The gelding runs in Saturday's Listed June Stakes (1200m) as part of his lead-up to next month's Ramornie Handicap at Grafton.

Robb has just eight horses in work but is leading the Wyong premiership ahead of Group One-winning trainers Allan Denham, Kim Waugh and Steve Farley, something that makes him justifiably proud.

"Even though I'm a bit short of horses I've got a very busy schedule." Robb said.

"I've only got eight in work and I trialled two at Newcastle this morning, I've got three racing tomorrow and two on Sunday.

"I'm leading the Wyong premiership, not by much with Allan Denham snapping at my heels.

"But he's got about 30 horses as has Kim Waugh and Crusher Farley so I'm doing pretty well.

"Ideally I'd like between 12 and 14 horses. I've lost a couple lately through injury and retirement."

A last-start second to Disciple on May 11, Big Bonanza will have to contend with a wide barrier and apprentice Shaun Guymer will be in charge of getting him into a forward position.

"I expect Zaratone to be leading and hopefully Big Bonanza can get up there and take a sit off him," Robb said.

"The Ramornie is his grande finale this preparation. I still expect him to go well at Randwick and he will go back there in a couple of weeks and then to Grafton.

"If he can run in the first six I will be happy because he hasn't raced for nearly a month.

"He was supposed to trial on Monday at Newcastle but they were changed to Friday. Luckily I was able to give him a grass gallop at Wyong instead."

Guymer, who is indentured to Farley, will also ride Big Bonanza's stablemate Howdiddydoit in the 1200m benchmark 80.

"Shaun rides a fair bit of work for me and rides well so it's good to have him on," Robb said.

Big Bonanza was an $11 chance with TAB's fixed odds on Friday in an open market in which She's Clean was the $5.50 favourite.

The track rating for Randwick was upgraded into the dead range on Friday.