While many other Derby aspirants will be in the Randwick Guineas (1600m) a week later, before going on to the Rosehill Guineas (2000m) on March28, Walter believes that is less than ideal.

The Warwick Farm trainer said he believed the demise of the Canterbury Guineas over 1900m in favour of the Randwick feature meant the staying three-year-olds did not get the necessary preparation for the 2400m Classic on April11.

''Since they abandoned the Canterbury Guineas it is a very poor progression of distances,'' Walter said.

''Orca will run over 1600m, then go to an 1800m race in preparation for the Rosehill Guineas and the Derby.''

Although he is still a maiden, Orca showed his promise in the Melbourne spring with his third to Whobegotyou in the Group2 AAMI Vase (2040m) which followed a close second to Sarem over 1600m at Caulfield.

At his first start since his 10th in the Victoria Derby, Orca finished an unlucky seventh over 1200m to Centennial Park at Rosehill on February7. AAP