The nerves have set in for South Australian trainer Jake Stephens as the race of his life approaches in Hong Kong on Sunday.

But the reason behind the shaking hands and the churning stomach are all positive.

Stephens saddles the eight-year-old, one-time crock and part-time polo pony Alcopop in the Group One Hong Kong Cup (2000m) on Sunday - and he thinks he's in with a chance.

"I'm loving it at the moment," Stephens said after watching Alcopop work at Sha Tin on Friday.

"In fact, it's making me nervous that he's going that well."

Alcopop goes around against a field that includes last year's winner California Memory, the Queen's and Gai Waterhouse's soon-to-be-acquired Carlton House, the French Derby winner Saonois and the Group One-winning French mare Giofra.

The world's highest-rated racehorse Cirrus Des Aigles, however, will be missing from the line up after suffering a slight leg injury that has failed to respond to treatment.

"It's a bit daunting, going into the barn every morning and working alongside the sort of people who are here," Stephens said.

"But it's fantastic - and the horse is going so well

"He's been working well, recovering well, loving the surface, changing legs as required, he's balanced.

"He's so good it's really making me nervous."

Alcopop's arrival in Hong Kong was accompanied by reports of concerning weight loss.

But Stephens, who travelled with the horse, said it was all down to a photograph taken at a bad angle as the horse stepped off the plane.

"I wasn't even aware of it until I read about it," he said.

Since then Alcopop has been trying to do more than he's been asked to.

"This morning he was the best he's been," Stephens said.

"We only wanted him to go even time and he did that with the rider's feet on the dashboard."

For Stephens and Alcopop's owners, the Hong Kong Cup is a twice-in-a-lifetime opportunity coming after their horse started favourite in the 2009 Melbourne Cup and ran an honourable sixth behind Shocking.

Since then he's endured an assortment of problems, all of them dealt with by his trainer who nursed him through them and produced him at the age of eight for what may well be his best preparation.

In his past three runs Alcopop has run second in the Caulfield Stakes to Ocean Park, second in the Caulfield Cup to Dunaden and then won the Mackinnon Stakes, turning the tables on Ocean Park who had won the Cox Plate in the meantime.

The performances won him an invitation to Hong Kong to run at a race meeting billed as the "world turf championships".

And Stephens has no doubt he deserves his place in the showpiece race in the world's most progressive and successful racing jurisdiction.

"He's done so much for us all," Stephens said.

"It's incredible that three years after we thought he'd done it all that he's doing even more."