Steven Arnold thought his chances of Melbourne Cup glory might have passed him by three years ago.

Arnold rode favourite So You Think in the 2010 Cup but was forced to settle for third in what was to be the champion horse's final Australian race before he went to Europe.

As a heavyweight rider, Arnold's opportunities are limited but on Tuesday at Flemington, he gets another chance in the Melbourne Cup on import Sea Moon, a horse he rates a "live chance".

"I thought So You Think might be one of my last chances," Arnold admitted.

"He had 56.5kg and ran third and ran super. But because there are so many international horses and jockeys coming over now, they are sort of taking up the top spots which I usually get.

"I can only ride the top four or five (in the weights) usually so it's making it harder to get rides, and that's why I'm rapt this year to get a live chance up in the weights."

Sea Moon is one of six runners for prominent owner Lloyd Williams.

Six years ago Arnold had the choice of rides between the Williams-owned pair of Gallic and Efficient and went with the former.

Gallic was scratched on race morning while Michael Rodd guided Efficient to Cup victory.

"But that's the game, I suppose," Arnold said.

"It would be great if this guy could do it for us."

Arnold has won a Cox Plate on So You Think and ridden a feature winner at Royal Ascot with Scenic Blast in the King's Stand Stakes.

He has to constantly work hard at his weight, being one of the tallest jockeys in Australia, and says the Melbourne Cup is the holy grail of Australian racing.

"That's what we work for," he said.

"A lot is said about my weight, but a lot of guys do it and don't get the rewards I've probably had over my career.

"I've got a pretty good incentive to do it."