Trainer John Thompson is relying on a gear change and and a drop in class to lift Primitivo to a long-awaited maiden win at Rosehill.

Luck in running would also be welcome in Saturday's TAB.com.au Handicap (1800m).

Primitivo, who has four minor placings from six starts, piqued the interest of Hong Kong buyers after his third in the Group Three Spring Stakes (1600m) at Newcastle in September.

He continued to attract interest when running to Assimilate in the Listed Canberra Guineas (1400m) in March.

But he found the going tough in the Group Two Tulloch Stakes (2000m) and Group Three Frank Packer Plate over the same distance.

Primitivo travelled wide throughout in the Tulloch Stakes at Rosehill in March before finishing eighth, 4-1/2 lengths behind subsequent Group One Australian Derby winner Levendi.

After a sluggish start in the Frank Packer Plate, Primitivo then became unbalanced and hit the running rail before finishing seventh.

"It's been very frustrating. He hasn't had much joy," Thompson said.

There was also a setback off course when a traffic accident prevented Primitivo from racing at Warwick Farm in March, a missed opportunity that disrupted his program and scuppered any chance of him running in the Australian Derby.

In a bid to help the best maiden in his stable justify his favouritism for Saturday's race, Thompson has added blinkers to Primitivo for the first time.

"The blinkers and a drop back in grade will hopefully let him turn it around," he said.

Thompson also saddles up seven-year-old gelding Maurus ($14) in the Listed Lord Mayor's Cup (2000m) in what shapes as a prelude for a trip to Brisbane for the Group One Doomben Cup (2000m) on May 19.