Rob Heathcote's Group One adventure continues with Woorim and Buffering in Melbourne then Tomboy in the Coolmore Classic in Sydney.

Trainer Rob Heathcote will continue his Group One adventure in two states with Tomboy confirmed a definite starter in the Coolmore Classic at Rosehill on Saturday.

Tomboy impressed with her final hard gallop on the course proper at Eagle Farm last Saturday and is booked on a flight to Sydney on Wednesday for the 1500-metre feature.

Heathcote is enjoying the ride of a lifetime and expects Tomboy to be competitive on her first interstate trip.

The four-year-old had won seven of her last nine starts before an unlucky second to Steel Zip in the Listed Tattersall's Members' Cup (1600m) at Eagle Farm on March 3.

Stewards reported Tomboy was galloped on and pulled up lame following the race.

Heathcote has been training for 12 years and won his first Group One with Woorim in the Oakleigh Plate at Caulfield in February.

He hopes to add the Group One William Reid Stakes (1200m) at Moonee Valley on Friday night to his honour board when he saddles up Woorim and Buffering.

"I've had more Group One runners in the last few months than I've had in the previous 12 years I've been training," Heathcote said.

"It's been a real buzz and it's fantastic to be competitive at this level."

Buffering has been ultra-competitive at Group One level with placings at his past three starts this campaign, including his latest when beaten in a photo-finish by Hay List in the Newmarket Handicap (1200m) at Flemington on March 10.

"The Coolmore is a big jump in class for Tomboy but I expect her to run very well," Heathcote said.

"She's proven herself in Brisbane and the only doubt is whether she's got the class to measure up in this company.

"But I take a lot of comfort after Craig Williams rang for the ride."

Heathcote hadn't planned on Williams taking the mount.

"I expected Jim Byrne to ride Tomboy until he rang on Saturday to tell me he'd been stood down by stewards," he said.

Byrne is due to appear before Racing Queensland stewards, possibly this week, after returning a positive test to an appetite suppressant.

"I deliberately held off booking a flight for Jim until Monday as I wasn't sure whether Tomboy would get a run," Heathcote said.

"She's a certain starter now but I got a real shock when Jim rang to tell me his news."

Meanwhile, Heathcote won't die wondering with Buffering and Woorim in their battle with Hay List in the William Reid.

"Hay List deserves to be an odds-on favourite but Buffering can make it hard for him," Heathcote said.

"We won't be handing it on a plate to Hay List and we'll put the pressure on early if they plan to lead on him.

"The small field in a fast-run race will also suit Woorim."