Royal Symphony retains Caulfield Guineas favouritism after the barrier draw and his jockey Dwayne Dunn maintains faith the colt will bounce back from his first defeat.

Dunn's wife Amanda is a part-owner of Royal Symphony and on Tuesday drew barrier nine for the colt in the capacity field of 16 plus one emergency for Saturday's $2 million 1600m Group One race for three-year-olds.

Despite drifting slightly from $3.80 to $4, Royal Symphony remains at the head of the market.

Trained by Tony McEvoy, the colt put together four wins before having his colours lowered for the first time when fourth in the Guineas Prelude (1400m) on October 1.

Royal Symphony still ran the fastest last 600m of the race in 33.91 seconds, coming from back in the field and Dunn is confident the colt can win on Saturday when he will wear winkers.

He acknowledges it is a defining race in Royal Symphony's career.

"He's had such a big boom on him," Dunn said.

"He was defeated the other day and we were all a bit disappointed because we'd like him to keep winning, but he probably ran the fastest last 400 metres of his life and he got beaten.

"He's telling us that he's still there.

"His jump-out since that race was fantastic and I'm hoping winkers do the job.

"But this is a turning point in his life because if he fails again he's just another horse. So we're hoping he'll turn up and run extremely well and keep the dream alive."

Dunn is hopeful the middle draw is a good one but much will depend on the pattern of the day.

"The track might be a mad run-on track and you're in the right spot or it could be a mad leaders' track and it wouldn't matter what barrier you drew," he said.

"So that will only be determined on the day whether it will be a good barrier or not."

The only filly in the field, Blue Diamond Stakes winner Catchy, has barrier three and is at $5 while Godolphin's Kementari ($5.50) has gate 10.

Godolphin trainer James Cummings has decided to also run Sanctioned who arrived in Melbourne from Sydney on Tuesday morning after running fourth in Saturday's Group One Spring Champion Stakes.

New Zealand colt Summer Passage has the outside barrier while Bill Stutt Stakes winner Showtime has barrier one.

The Mick Price-trained Mighty Boss is the emergency.