"I was thinking originally that I would just go straight to the Australian Derby but he did so well in his week in the paddock that we will go to the Rosehill Guineas now for sure and then into the Derby. He has just come back magic."
Marsh admits that Scorpz will be seen at his best when he is back over 2400m.
"The Rosehill Guineas is not a race I am worried about. All I want to do is give him a fitting run for the Derby and that is when he will be peaking again. That is the race for him."
The winner of three of his 11 starts, the majority of Scorpz's form is on top of the ground, given the firm underfoot conditions that have prevailed in New Zealand over the past four months, but his trainer believes he would handle a rain-affected surface should Sydney's fickle autumn weather intervene.
"I think he probably would handle a softer surface," Marsh said. "If it was a heavy track in the Derby and we went five weeks between runs you might come up a little bit short, so we don't want to chance anything and that is another reason for the Rosehill Guineas run.
"He was very strong at the line and through the line in our Derby, so I have no doubt about his ability to get a testing 2400m."
Opie Bosson has been engaged to ride Scorpz in the Rosehill Guineas, with a decision pending on a rider beyond that.
Marsh is also confident the New Zealand 3-year-old form will be more than competitive with the Australian middle-distance horses in what shapes as a strong classic crop on both sides of the Tasman.
"I think we have a good crop of three-year-olds here and they will stand right up to the Australians to be honest. Once we get over ground, Sherwood Forest and our horse are very strong staying horses and I think they'd be up to any Derby."
Marsh knows what it takes to prepare a 3-year-old classic winner across the Tasman, having saddled Sofia Rosa to win the Group 1 Australian Oaks (2400m) in 2016.
He also prepared Lucia Valentina to win a Group 3 race and finish runner up at Group 2 level before she won the 2014 Group 1 Vinery Stud Stakes (2000m) for Newcastle trainer Kris Lees and was then placed in the Australian Oaks.
Meanwhile, Marsh, who is currently second on the New Zealand Trainers' premiership behind Jamie Richards, will line up one-win filly Kaipaki Road in Saturday's Group 1 Al Basti Equiworld Dubai New Zealand Oaks (2400m) at Trentham.
"We'd love to see some easing in the ground but I am not sure whether we will get much of that," Marsh said of the daughter of El Roca.
— NZ Racing Desk
