Victorian Peter Mertens hasn't ridden in Sydney for almost five years but didn't need much persuasion to make the trip to Rosehill on Saturday.

Mertens has answered a call from trainer David Atkins to ride in-form mare Panko in the Become An ATC Member In 2013 Handicap (1900m) as she strives to take another successful step up in grade.

The trainer-jockey combination has history, winning the 2006 Eye Liner Stakes and 2007 Canterbury Classic with Impaler.

It was the friendship forged during that period which led to Atkins' call and Mertens didn't hesitate to book a flight north.

"Not for Dave, he's a very smart man. I understand how he trains his horses and he wouldn't call me for no reason, if he didn't think it was a genuine chance," Mertens said.

The hoop was also booked to ride Panko in Thursday's Gosford Cup but Atkins scratched her from the Listed race in favour of Saturday's assignment.

Mertens believes the trainer made the right decision and punters agree with Panko the early $4.60 favourite for Saturday's race.

"Looking at the race at Gosford, she was probably a top three or four chance maybe, and in Sydney, that sort of race looks to be at her mercy," he said.

"She's obviously a horse on the way up. Her last win, she came off a slow pace and had a good turn of foot. She's going to stay all right."

Merten's foray into Sydney will be his first since 2008 when he partnered the Bart Cummings-trained Sirmione in the Ranvet Stakes.

Most of his trips north have been for stakes races, adding weight to his decision to ride at Rosehill during a non-carnival weekend.

But Sydney isn't the only destination on Mertens' travel itinerary.

He will also be going back and forth to Tasmania to ride Geegees Blackflash who he won five straight races aboard last summer including the Hobart Cup.

The gelding is being aimed at a defence of his Hobart Cup crown.

Mertens has ridden 26 winners in Victoria this season and celebrated a Group One victory in Adelaide in April aboard the Clarry Conners-trained Invest in the Schweppes Oaks.

The jockey hasn't ruled out the up-and-coming Panko as the horse who might deliver his next major success.

"I'm just trying to find the next Group winner along with everyone else," he said.

"You never know (about Panko), especially four-year-old mares, they can come out of the woodwork."