Trainer Brendan McCarthy has taken encouragement from Blondie's first-up win at Sandown as he plots a Thousand Guineas campaign for the talented filly.

Those lofty ambitions will be put to the test on Saturday at Moonee Valley when Blondie runs in the Listed Atlantic Jewel Stakes (1200m).

Blondie was an impressive winner at Moonee Valley on debut in January, earning a crack at the Group One Blue Diamond Stakes but she finished last and emerged from the race with an injury to her pelvis.

She made her return at Sandown last week and McCarthy was thrilled to see the filly ease out of an on-speed position under apprentice Ethan Brown before powering to the front to win the midweek race by just under a length.

"Something I tried with her the other day was just to get her to settle," McCarthy said.

"She could have led but it was something that I wanted Ethan to do on her.

"And when she did go back, she switched off and she actually switched off a little bit too much which I think is a great sign for the future."

McCarthy believes that trait will enhance her chances to stretch out to the Thousand Guineas distance of 1600m.

"She had only had the two starts before the Sandown race last week and the thing about her, if she can get the ground I think she's got the ability to do something a bit special," McCarthy said.

"She's got a bit of X-factor about her."

McCarthy was surprised Blondie was sent out at double figure odds at Sandown and the filly is at $15 for her step up in class in the Atlantic Jewel which features a number of Thousand Guineas hopefuls.

"It's a tough race," McCarthy said.

"It's not the best three-year-old fillies around, but most of them are there.

"I expect her to be really competitive."