Matt Cumani believes Victorian visitor Declares War has thrived since arriving in Brisbane, boosting the trainer's hopes of a good showing from the gelding in the Queensland Derby.

A last-start winner over 2000m at Flemington, Declares War pleased his trainer in a course proper gallop at Eagle Farm on Tuesday ahead of Saturday's 2400m Group One race for three-year-olds at the same track.

"He came up last Tuesday and settled in really well," Cumani said.

"He seems to be flourishing. I think he's in his best-ever form and we'll just have to see if that's good enough for a Derby.

"It will be interesting to see the final field on Wednesday. He's about a 15/1 shot at the moment and I think that's probably about fair.

"We've tried him in Group class before and it hasn't worked but we then gelded him and he was unlucky in his first start as a gelding and then won at Flemington carrying a lot more weight than the runner-up.

"Whether that's good enough to take that step back up into Group class, I'm not sure."

Cumani said Declares War seemed to handle the surface and the turn well in his gallop at Eagle Farm.

"So I'm hopeful that if he can handle the grade and he appreciates the extra distance, he'll run a big race," he said.

Victoria's premier jockey Craig Williams is booked for the ride.

Declares War has had five starts for Cumani after having his first five starts for Darren Weir.

The three-year-old started three times in Group Two races during the Melbourne autumn carnival without winning, before he was gelded.

The Chris Waller-trained Nobu was the $4 Derby favourite on Tuesday ahead of the Phillip Stokes-trained Mr Quickie at $6.

The Queensland Derby is one of three Group One races on Saturday's Eagle Farm program along with the Stradbroke Handicap and J J Atkins Plate.