Melbourne colt Ruthven heads to Doomben to run in his third Derby for the season after finishing fourth in the Australian Derby in Sydney and second in the South Australian equivalent.

Trainer Ciaron Maher believes Ruthven is a preparation or two away from reaching his full potential but he still rates the colt a good chance in Saturday's Group One Queensland Derby (2200m).

Maher has given Ruthven plenty of time to mature and did not start to push the colt until the late spring.

"He is leggy and raw-boned. But he is getting better with each start and we felt he deserved another chance at a Derby," Maher said.

"Being a big horse and the way he races it would probably have been better for the Derby to have been over 2400 metres at Eagle Farm. But he is at Doomben and I think he can run a race.

"Hugh (Bowman) had a sit on him on Tuesday morning and reported he felt good."

Maher, whose Queensland record includes the 2015 Stradbroke Handicap and Tatt's Tiara with Srikandi, is not sure Ruthven will be ready for the spring carnivals.

"I think when he matures he will be a top galloper but whether that is in the spring or the autumn remains to be seen," he said.

Maher will also have two-year-old filly Aloisia in the Group One J J Atkins Stakes.

"She is going well and I have always thought the 1600 metres of the Atkins would be ideal," he said.

Ruthven was beaten in Adelaide by Volatile Mix who is owned by Graham and Linda Huddy who are after a fourth win in a Derby.

The Huddys owned Shoot Out, who won the 2011 Australian Derby and Preferment, winner of the 2014 Victoria Derby.

Trainer Darren Weir kept Volatile Mix up to the mark by sending him around in a Caloundra barrier trial on Tuesday when he ran fourth.

At his last start Volatile Mix was a nose second to Order Again in the Grand Prix at Eagle Farm two weeks ago.

Order Again will miss the Derby with trainer Brian Smith unhappy with his work earlier this week.