Brett Prebble is pinning his hopes on Hong Kong sprinter Lucky Nine to end his lean spring carnival on a high note in the Group One VRC Sprint Classic.

Lucky Nine went within a short half-head of winning the Manikato Stakes at Moonee Valley at his Australian debut last month and Prebble is adamant the horse is capable of much better on Saturday.

The gelding will take on 13 rivals in the $1 million straight-track sprint at Flemington with added fitness on his side.

"He's a very happy horse and a very fit horse now. I just hope he brings his A-game and he'll show them what it's all about," Prebble said.

Prebble delayed his return to Hong Kong until after the Cup carnival but he is yet to post a big race winner this season in Melbourne.

He has ridden two city winners during the spring but says he can't wait for Saturday.

"It will be nice when I put the foot down for one to go," Prebble said.

"It's been hard to find fast ones at the moment."

Lucky Nine won the KrisFlyer International Sprint in Singapore in May and if successful on Saturday he will earn a $600,000 bonus.

The bonus is offered by the Victoria Racing Club if the winner of the VRC Sprint Classic has also captured a leg of the Global Sprint Challenge outside Australia in the preceding 12 months.

A win to Lucky Nine would also keep alive his chances of a $US1 million bonus for any horse who can claim three legs of the Global Sprint Challenge in three different countries.

To achieve that Lucky Nine would have to return home and win the Hong Kong Sprint in December.

Lucky Nine is favourite for Saturday's race in which he will face a rematch with his Manikato Stakes conqueror Buffering.

Prebble said Lucky Nine's fitness had improved considerably since the Moonee Valley race.

"He went close at Moonee Valley but that was very much below his best," the jockey said.

"I think he has come on a lot and you'll see a different horse on Saturday."