Trainer Brendan Mackay has taken a line through a rival runner to confirm his belief Nardoo won't be out of place at Doomben.

Nardoo steps up from a midweek maiden to an open three-year-old sprint on Saturday in the Garrards Horse and Hounds Hcp (1110m).

She was an impressive debut winner at Doomben last month, winning an 1110m race by more than six lengths in 1:04.21sec.

She covered the final 600m in 33.34, a second quicker than Board Director, winner of the other three-year-old race on the day.

"Board Director then came out and ran a great race in a Saturday open three-year-old. He finished third after racing deep the entire trip and they ran smart time," Mackay said.

"I know you can't always take note of times and perhaps it won't work out. But I think it at least gives us a guide," he said.

Apprentice James Orman will again ride Nardoo and his 2kg claim will reduce the filly's weight to 52kg.

Nardoo is by 2008 Todman Slipper winner Krupt whose Golden Slipper hopes were dashed by injury and he was retired to stud.