Filly’s chance to prove herself against quality stablemates in Adelaide Group 1.

The Group 1 credentials of two Ciaron Maher's Robert Sangster Stakes runners are not for debate and Australia's leading trainer is confident it is only a matter of time before his other representative joins them.

Ruthless Dame will chase a maiden win at the highest level in the 1200-metre fillies and mares event worth $500,000.

The three-year-old was well beaten last start in the Coolmore Classic (1500m) but was nosed out in the Surround Stakes (1400m) despite a torrid run the start prior, having been a close-up third in the Group 3 Manfred Stakes (1300m) won by Jacquinot at her first start this campaign.

"She arguably should have beaten Jacquinot at Sandown and backed it up with a huge run in the Surround," Maher, who trains with David Eustace, said.

"She's of that (Group 1) ability. She's sharp, we've kept her fresh, she trialled well, is very fit and the track won't affect her."

The daughter of Tavistock is the most lightly-raced runner in Saturday's race at Morphettville, having won her only two other starts, which came as a two-year-old early last year.

Conversely, stablemate Bella Nipotina is the most experienced runner in the Sangster Stakes, having won six of 37 starts including last year's Manikato Stakes at Group 1 level.

The five-year-old also boasts five Group 1 minor placings, including a Black Caviar Lightning third and William Reid Stakes second earlier this campaign and Maher said she had bounced out of her third placing in the $4 million The Quokka in Perth.

"She's in super order," Maher said. "She's been very consistent this prep, she flew back (from Perth) and didn't bat an eye lid at all and her work was sharp on Monday."

Bella Nipotina (Ben Melham) will jump from barrier five, with Ruthless Dame (John Allen) in 12, while Marabi (Ben Allen) has drawn barrier seven.

Maher is happy with the Oakleigh Plate winner's condition but will wait until closer to race time to commit to a start with the trainer worried about the prospect of a wet track for the daughter of I Am Invincible.

The Morphettville track was rated a Soft 6 on Thursday morning but up to 10mm of rain is predicted on Friday.

"She's doesn't like the wet, so I'll just wait and see, but I think she's ready to run a race," Maher said.