A groundswell of support for Appearance to keep an unbeaten record this campaign has been complemented by an endorsement of her rich talents from rival trainer Chris Waller.

Appearance has been heavily backed to beat the Waller-trained Boban in the weight-for-age Apollo Stakes at Randwick.

A three-time Group One winner, Appearance is expected to challenge Boban for favouritism on Saturday after firming from $3.70 to $2.80 with most wagering operators.

It's a betting move that comes as no surprise to Waller as he weighs up Boban's three-length defeat into fifth behind Appearance in the Expressway Stakes.

"He was a little bit below what I expected but I stress that Appearance is a very good horse," Waller said.

"And there were some other very good horses in the race and that's Sydney racing. It's always very competitive."

Boban is holding his place at the top of market at $2.30 and Waller expects better from the four-year-old, especially since the Randwick track was upgraded to the slow range on Friday with further improvement forecast.

"I'm looking for more on Saturday," he said. "He's second-up over a more suitable trip (1400m)."

Two of Boban's eight career wins have been at his second run back from a spell, including a Group Three victory over the Apollo Stakes course during an undefeated spring.

Appearance is yet to post a second-up win but her explosive Expressway victory points to her autumn campaign being as profitable as her 2013 one when she claimed the Coolmore Classic and Queen Of The Turf Stakes at Group One level.

The Apollo Stakes will be run without Boban's stablemate Sizzling and the Peter Snowden-trained Pinwheel who will both contest the Group One Futurity Stakes at Caulfield.

But last year's winner Alma's Fury is set to take his place as a $35 chance after his scratching from a Randwick support race.

Joining Sizzling and Pinwheel in Melbourne will be the Hawkes Racing-trained Not Listenin'tome.

The three-year-old has been scratched from the Southern Cross Stakes to take on his own age as the $1.90 favourite in the Zeditave Stakes at Caulfield.