Jockey Cory Parish considers the Sydney Cup ride on Boom Time in the $2 million race at Randwick the greatest opportunity of his career.

Parish is a regular track rider for the powerful Lindsay Park establishment at David Hayes' Euroa property in country Victoria and 20 of his 30 winners this season have been for the stable.

Parish has had a couple of Group One opportunities for Lindsay Park this season for a fourth on Tashbeeh in the Memsie Stakes and an unplaced run on Fuhryk in the Australian Guineas.

But Boom Time in Saturday's Sydney Cup (3200m) has him excited.

"I would say it would be my biggest opportunity," Parish said.

"Obviously I've had Group One rides but this is quite a prestigious Group One so I would say it would be the best opportunity that I've had in my career."

Parish, 27, was born in New Zealand and began his career there.

He has been based in Victoria for about four years, trying to build his way up, and during this year's autumn carnival he rode his first Australian stakes winner on two-year-old Ploverset in a Listed race at Flemington.

Ploverset is also trained by David and Ben Hayes and Tom Dabernig.

Parish was confirmed as the rider of Boom Time on Tuesday morning, the first time he will ride the horse in a race.

"I do a fair bit of trackwork for them and I've ridden him a fair bit in track gallops," he said.

"I even said to Tom a little while back, 'if you could try to get me on this horse, I think he would suit me'.

Parish believes Boom Time is suited to a rider who can use the whip in the left hand.

The jockey will be riding at Randwick for the first time.

Boom Time was entered for the rescheduled Sydney Cup after a frontrunning win under leading apprentice Beau Mertens over 2425m at Caulfield last Saturday.

The Sydney Cup was originally run on April 8 but was declared a no-race when two horses came down just after the winning post the first time.

Almoonqith, who was trained by the Hayes-Dabernig team, had to be euthanised.

Parish was impressed with Boom Time's Caulfield win when he kicked around the home corner and was strong to the line.

"If he can do the same sort of thing and if he can run out the 3200 metres I think he'll be just as competitive," he said.

"Obviously he's rock-hard fit and if he can just get a nice run through the race I think he can be in with a live chance."