David Hayes is worried about this one thing...

Ka Ying Rising is the short-priced favourite with many bookmakers to take out the $20 million Everest this Saturday.

But the win isn’t guaranteed.

The eight-time Group 1 winner’s trainer David Hayes has revealed his biggest worry for Ka Ying Rising in The Everest.

And guess what?

It’s actually not the other runners - it’s whether the Hong Kong superstar can adapt to the new environment of a packed and likely raucous Randwick Racecourse.

“Probably that the horse is in a new environment, racing on a new track for the first time instead of Sha Tin. That's probably my biggest concern,” Hayes told SEN Breakfast with Vossy & Brandy.

“I hope he behaves himself pre-race.

“But we've put a lot of strategies in place to make sure he's nice and calm. Hopefully that pays off.

“Pre-race if he's reasonably calm, I'll be quietly confident.”

Regarding which horse could give Ka Ying Rising a scare, Hayes believes nearly half the field could knock off his horse.

“I don't think there's one individual, but Chris Waller’s trio of horses (Joliestar, Lady Shenandoah & Angel Capital) are very, very good,” Hayes admitted.

“The (Wayne, John & Michael) Hawkes' horse, Briasa, is an inform last-start winner.

“My son's horse (Will, Ben & JD Hayes), War Machine has hit form at the right time and got a great barrier.

“So, they're all really classic Group 1 horses.

“My thing is, my horse is a specialist sprinter, and I think these other horses, if you ask the connections, are probably better at 1400m or a mile.”

Click here to see The Everest barrier draw.