The threat of a rain-affected surface and the vagaries of Flemington's famed straight six both represent unknowns for Lucky Nine in Saturday's Group One VRC Sprint Classic, but confident trainer Caspar Fownes is more concerned about the former than the latter.

Patchy rain in Melbourne on Friday had Lucky Nine facing the prospect of wet going for the first time in his 35-start career, but Fownes wasn't worried about the tricky straight track - especially as it is something of a home ground for jockey Brett Prebble.

"He is unknown on the wet, so we don't want that, and have to run the risk of him not handling it," Fownes said. "The track conditions would be the only excuse. He is as I can have him and I think he will be fine up the straight, he was unlucky up the straight at Sha Tin last year, when I thought he should have won, and that's where they go flat out over 1,000m. The way they run the 1,200m races at Flemington should suit him more as far as pace goes."

Prebble is a veteran of the Melbourne Spring Carnival, winning the feature sprint in 1999 on Pharein, and seems to have been drawn ideally in nine.

"Brett will work it out for himself," Fownes said. "They've been coming down the centre of the track all week and that's where he has drawn. It is the perfect spot really. As long as we land in a good spot, and track up behind something that can take us into the race. Ideally I see him getting some cover in behind and then peeling off their heels at the 300m and just going whooshka. He should be too strong for them the last little bit."

Australian bookies had Lucky Nine a $3.60 favourite ahead of Buffering ($8), the horse that narrowly beat him last start in the Manikato Stakes at Moonee Valley. Fownes believes Prebble erred in not keeping Lucky Nine closer as they turned in that race and that he should have won.

"That run was a bottler and he was unlucky," Fownes said.

"It's unfortunate what happened - if Brett had been a bit sharper and tried to roll 30 or 40 yards earlier it would have been game over."

Lucky Nine faces some other familiar foes from the Manikato including Bel Sprinter and the horse Fownes rates as the major danger, Rebel Dane.

"I think Rebel Dane will be better up the straight than he was at Moonee Valley and Peter Snowden's sprinter Epaulette - they are the two," he said.

A pay day of A$1.2 million (HK$8.8 million) awaits connections if Lucky Nine can beat a strong field of Aussie sprinters, with the Victoria Racing Club offering a A$600,000 on top of the A$600,000 first prize if a winner of a previous leg of the Global Sprint Challenge is successful.

If Lucky Nine triumphs on Saturday he will be chasing a US$1 million bonus in December's Group One Hong Kong Sprint at Sha Tin.