Ciaron Maher has been leaving nothing to chance as he prepares unbeaten Merchant Navy for two important Group One races.

The first of those is Saturday's $1 million Golden Rose at Rosehill followed by the Caulfield Guineas three weeks later.

Undefeated in four starts, Merchant Navy will have his first run in Sydney on Saturday.

But the colt has been given extensive exercise on his 'Sydney' leg working the reverse way at Caulfield.

He even had a trip to Sydney last autumn, but failed to get a start when an emergency for the ATC Sires' Produce Stakes at Randwick.

"He had a couple of gallops up there in that direction and I think the trip up there brought him on as a horse," Maher said.

"As a two-year-old he was a bit of a baby and it made him grow up a bit."

After three wins as a two-year-old, the last two over 1400m, Merchant Navy returned to racing with a first-up victory in the McNeil Stakes (1200m) at Caulfield on September 2.

Maher said the three weeks into the Golden Rose and another three weeks into the Caulfield Guineas suited perfectly.

"It's a nice program with a trip in between and a couple of gallops," Maher said.

"If they're racing every fortnight you really only get one opportunity to give them a decent gallop.

"Three weeks is the program we set for him early and so far so good."

Merchant Navy galloped right-handed at Caulfield last Tuesday and will continue his preparation for Saturday's race from Gerald Ryan's Rosehill stable having travelled to Sydney over the weekend.

Mark Zahra, who has ridden the colt in three of his four wins, has the ride on Saturday.

Merchant Navy is the $9 third favourite for the Golden Rose with the Ryan-trained Menari the $2.50 favourite and Pariah a $6 chance.