"It definitely knocked our confidence, we know it is hard to turn a horse around 15 lengths in a week," said Latta.
"But we had blood tests taken and they were fine and we think a couple of things this week should suit him better.
"Maybe he was ridden a bit closer to the speed than he likes last Saturday and obviously the track was very heavy.
"So on a better, bigger track at Randwick being ridden back in the field we are hoping to see something more like his best."
One of the north's hardest-working jockeys in Jonathan Riddell will take the reins this Saturday, having his first ride in Australia in three years.
Latta will most likely decide today whether New Zealand Oaks winner Sentimental Miss also heads to Sydney for the A$1 million ATC Oaks on Saturday week.
"The trip is still very possible but we are waiting to see what we think the track conditions will be like.
"We wouldn't go if they were likely to be firm or heading that way but we know she can handle the wet so if it looks like the rain might stick around she is likely to go."
One horse Latta was hoping to take to Australia has already gone without her, with stable favourite Five To Midnight having joined the Patrick Payne stable in Victoria.
"I'm disappointed to see him go and was hoping to take him to Queensland this winter but he has already left," said Latta.
Australian Derby
Randwick, Saturday, A$2m (2400m)
• 1 — Extra Brut (56.5kg) — Barrier 18 T: Ciaron Maher & David Eustace J: Sam Clipperton
• 2 — Madison County (56.5kg) — Barrier 11 T: Murray Baker & Andrew Forsman J: Tommy Berry
• 3 — In A Twinkling (56.5kg) — Barrier 15 T: Jamie Richards J: Opie Bosson
• 4 — Arrogant (56.5kg) — Barrier 12 T: Michael Moroney J: Craig Williams
• 5 — Chapada (56.5kg) — Barrier 13 T: Michael Moroney J: Damien Oliver
• 6 — Surely Sacred (56.5kg) — Barrier 6 T: Tony Pike J: Damian Lane
• 7 — Platinum Invador (56.5kg) — Barrier 14 T: Lisa Latta J: Jonathan Riddell
• 8 — Global Exchange (56.5kg) — Barrier 8 T: Ciaron Maher & David Eustace J: Kerrin McEvoy
• 9 — Stars of Carrum (56.5kg) — Barrier 10 T: Robbie Laing J: Hugh Bowman
• 10 — Aramayo (56.5kg) — Barrier 19 T: James Cummings J: Tim Clark
• 11 — Angel of Truth (56.5kg) — Barrier 4 T: Gwenda Markwell J: Corey Brown
• 12 — The Chosen One (56.5kg) — Barrier 17 T: Murray Baker & Andrew Forsman J: Blake Shinn
• 13 — Cossetot (56.5kg) — Barrier 3 T: James Cummings J: Glyn Schofield
• 14 — Declarationofheart (56.5kg) — Barrier 1 T: Anthony Freedman J: Mark Zahra
• 15 — Costello (56.5kg) — Barrier 9 T: David Payne J: Jason Collett
• 16 — Twinspier (56.5kg) — Barrier 7 T: Trent Busuttin & Natalie Young J: Luke Nolen
• 17 — Shaman (56.5kg) — Barrier 2 T: Anthony Cummings J: Travis Wolfgram
• 18 — Frankely Awesome (54.5kg) — Barrier 16 T: Kris Lees J: James McDonald
• 19e — Yulong Tavion (56.5kg) — Barrier 5 T: Mick Price J: Brenton Avdulla